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Karaglani M, Agorastos A, Panagopoulou M, Parlapani E, Athanasis P, Bitsios P, Tzitzikou K, Theodosiou T, Iliopoulos I, Bozikas VP, Chatzaki E. A novel blood-based epigenetic biosignature in first-episode schizophrenia patients through automated machine learning. Transl Psychiatry 2024; 14:257. [PMID: 38886359 PMCID: PMC11183091 DOI: 10.1038/s41398-024-02946-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Schizophrenia (SCZ) is a chronic, severe, and complex psychiatric disorder that affects all aspects of personal functioning. While SCZ has a very strong biological component, there are still no objective diagnostic tests. Lately, special attention has been given to epigenetic biomarkers in SCZ. In this study, we introduce a three-step, automated machine learning (AutoML)-based, data-driven, biomarker discovery pipeline approach, using genome-wide DNA methylation datasets and laboratory validation, to deliver a highly performing, blood-based epigenetic biosignature of diagnostic clinical value in SCZ. Publicly available blood methylomes from SCZ patients and healthy individuals were analyzed via AutoML, to identify SCZ-specific biomarkers. The methylation of the identified genes was then analyzed by targeted qMSP assays in blood gDNA of 30 first-episode drug-naïve SCZ patients and 30 healthy controls (CTRL). Finally, AutoML was used to produce an optimized disease-specific biosignature based on patient methylation data combined with demographics. AutoML identified a SCZ-specific set of novel gene methylation biomarkers including IGF2BP1, CENPI, and PSME4. Functional analysis investigated correlations with SCZ pathology. Methylation levels of IGF2BP1 and PSME4, but not CENPI were found to differ, IGF2BP1 being higher and PSME4 lower in the SCZ group as compared to the CTRL group. Additional AutoML classification analysis of our experimental patient data led to a five-feature biosignature including all three genes, as well as age and sex, that discriminated SCZ patients from healthy individuals [AUC 0.755 (0.636, 0.862) and average precision 0.758 (0.690, 0.825)]. In conclusion, this three-step pipeline enabled the discovery of three novel genes and an epigenetic biosignature bearing potential value as promising SCZ blood-based diagnostics.
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Affiliation(s)
- Makrina Karaglani
- Laboratory of Pharmacology, Department of Medicine, Democritus University of Thrace, GR-68132, Alexandroupolis, Greece
- Institute of Agri-food and Life Sciences, University Research & Innovation Center, H.M.U.R.I.C., Hellenic Mediterranean University, GR-71003, Crete, Greece
| | - Agorastos Agorastos
- Institute of Agri-food and Life Sciences, University Research & Innovation Center, H.M.U.R.I.C., Hellenic Mediterranean University, GR-71003, Crete, Greece
- II. Department of Psychiatry, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, GR-56430, Thessaloniki, Greece
| | - Maria Panagopoulou
- Laboratory of Pharmacology, Department of Medicine, Democritus University of Thrace, GR-68132, Alexandroupolis, Greece
- Institute of Agri-food and Life Sciences, University Research & Innovation Center, H.M.U.R.I.C., Hellenic Mediterranean University, GR-71003, Crete, Greece
| | - Eleni Parlapani
- Ι. Department of Psychiatry, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, GR-56429, Thessaloniki, Greece
| | - Panagiotis Athanasis
- II. Department of Psychiatry, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, GR-56430, Thessaloniki, Greece
| | - Panagiotis Bitsios
- Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, GR-71500, Heraklion, Greece
| | - Konstantina Tzitzikou
- Laboratory of Pharmacology, Department of Medicine, Democritus University of Thrace, GR-68132, Alexandroupolis, Greece
| | - Theodosis Theodosiou
- Laboratory of Pharmacology, Department of Medicine, Democritus University of Thrace, GR-68132, Alexandroupolis, Greece
- ABCureD P.C, GR-68131, Alexandroupolis, Greece
| | - Ioannis Iliopoulos
- Division of Basic Sciences, School of Medicine, University of Crete, GR-71003, Heraklion, Greece
| | - Vasilios-Panteleimon Bozikas
- II. Department of Psychiatry, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, GR-56430, Thessaloniki, Greece
| | - Ekaterini Chatzaki
- Laboratory of Pharmacology, Department of Medicine, Democritus University of Thrace, GR-68132, Alexandroupolis, Greece.
- Institute of Agri-food and Life Sciences, University Research & Innovation Center, H.M.U.R.I.C., Hellenic Mediterranean University, GR-71003, Crete, Greece.
- ABCureD P.C, GR-68131, Alexandroupolis, Greece.
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, 70013, Heraklion, Greece.
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Delphin N, Aust C, Griffiths L, Fernandez F. Epigenetic Regulation in Schizophrenia: Focus on Methylation and Histone Modifications in Human Studies. Genes (Basel) 2024; 15:272. [PMID: 38540331 PMCID: PMC10970389 DOI: 10.3390/genes15030272] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 06/15/2024] Open
Abstract
Despite extensive research over the last few decades, the etiology of schizophrenia (SZ) remains unclear. SZ is a pathological disorder that is highly debilitating and deeply affects the lifestyle and minds of those affected. Several factors (one or in combination) have been reported as contributors to SZ pathogenesis, including neurodevelopmental, environmental, genetic and epigenetic factors. Deoxyribonucleic acid (DNA) methylation and post-translational modification (PTM) of histone proteins are potentially contributing epigenetic processes involved in transcriptional activity, chromatin folding, cell division and apoptotic processes, and DNA damage and repair. After establishing a summary of epigenetic processes in the context of schizophrenia, this review aims to highlight the current understanding of the role of DNA methylation and histone PTMs in this disorder and their potential roles in schizophrenia pathophysiology and pathogenesis.
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Affiliation(s)
- Natasha Delphin
- School of Health and Behavioural Sciences, Faculty of Health Sciences, Australian Catholic University, 1100 Nudgee Rd, Banyo, QLD 4014, Australia; (N.D.)
| | - Caitlin Aust
- School of Health and Behavioural Sciences, Faculty of Health Sciences, Australian Catholic University, 1100 Nudgee Rd, Banyo, QLD 4014, Australia; (N.D.)
| | - Lyn Griffiths
- Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, 60 Musk Ave, Kelvin Grove, QLD 4059, Australia;
| | - Francesca Fernandez
- School of Health and Behavioural Sciences, Faculty of Health Sciences, Australian Catholic University, 1100 Nudgee Rd, Banyo, QLD 4014, Australia; (N.D.)
- Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, 60 Musk Ave, Kelvin Grove, QLD 4059, Australia;
- Healthy Brain and Mind Research Centre, Australian Catholic University, Melbourne, VIC 3000, Australia
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3
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Flynn LT, Gao WJ. DNA methylation and the opposing NMDAR dysfunction in schizophrenia and major depression disorders: a converging model for the therapeutic effects of psychedelic compounds in the treatment of psychiatric illness. Mol Psychiatry 2023; 28:4553-4567. [PMID: 37679470 PMCID: PMC11034997 DOI: 10.1038/s41380-023-02235-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023]
Abstract
Psychedelic compounds are being increasingly explored as a potential therapeutic option for treating several psychiatric conditions, despite relatively little being known about their mechanism of action. One such possible mechanism, DNA methylation, is a process of epigenetic regulation that changes gene expression via chemical modification of nitrogenous bases. DNA methylation has been implicated in the pathophysiology of several psychiatric conditions, including schizophrenia (SZ) and major depressive disorder (MDD). In this review, we propose alterations to DNA methylation as a converging model for the therapeutic effects of psychedelic compounds, highlighting the N-methyl D-aspartate receptor (NMDAR), a crucial mediator of synaptic plasticity with known dysfunction in both diseases, as an example and anchoring point. We review the established evidence relating aberrant DNA methylation to NMDAR dysfunction in SZ and MDD and provide a model asserting that psychedelic substances may act through an epigenetic mechanism to provide therapeutic effects in the context of these disorders.
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Affiliation(s)
- L Taylor Flynn
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
- MD/PhD program, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Wen-Jun Gao
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA.
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Magwai T, Shangase KB, Oginga FO, Chiliza B, Mpofana T, Xulu KR. DNA Methylation and Schizophrenia: Current Literature and Future Perspective. Cells 2021; 10:2890. [PMID: 34831111 PMCID: PMC8616184 DOI: 10.3390/cells10112890] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/09/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia is a neuropsychiatric disorder characterized by dissociation of thoughts, idea, identity, and emotions. It has no central pathophysiological mechanism and precise diagnostic markers. Despite its high heritability, there are also environmental factors implicated in the development of schizophrenia. Epigenetic factors are thought to mediate the effects of environmental factors in the development of the disorder. Epigenetic modifications like DNA methylation are a risk factor for schizophrenia. Targeted gene approach studies attempted to find candidate gene methylation, but the results are contradictory. Genome-wide methylation studies are insufficient in literature and the available data do not cover different populations like the African populations. The current genome-wide studies have limitations related to the sample and methods used. Studies are required to control for these limitations. Integration of DNA methylation, gene expression, and their effects are important in the understanding of the development of schizophrenia and search for biomarkers. There are currently no precise and functional biomarkers for the disorder. Several epigenetic markers have been reported to be common in functional and peripheral tissue. This makes the peripheral tissue epigenetic changes a surrogate of functional tissue, suggesting common epigenetic alteration can be used as biomarkers of schizophrenia in peripheral tissue.
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Affiliation(s)
- Thabo Magwai
- Department of Physiology, School of Laboratory Medicine and Medical Sciences, University of Kwa-Zulu Natal, Durban 4001, South Africa; (K.B.S.); (F.O.O.); (T.M.)
- National Health Laboratory Service, Department of Chemical Pathology, University of Kwa-Zulu Natal, Durban 4085, South Africa
| | - Khanyiso Bright Shangase
- Department of Physiology, School of Laboratory Medicine and Medical Sciences, University of Kwa-Zulu Natal, Durban 4001, South Africa; (K.B.S.); (F.O.O.); (T.M.)
| | - Fredrick Otieno Oginga
- Department of Physiology, School of Laboratory Medicine and Medical Sciences, University of Kwa-Zulu Natal, Durban 4001, South Africa; (K.B.S.); (F.O.O.); (T.M.)
| | - Bonginkosi Chiliza
- Department of Psychiatry, Nelson R Mandela School of Medicine, University of Kwa-Zulu Natal, Durban 4001, South Africa;
| | - Thabisile Mpofana
- Department of Physiology, School of Laboratory Medicine and Medical Sciences, University of Kwa-Zulu Natal, Durban 4001, South Africa; (K.B.S.); (F.O.O.); (T.M.)
| | - Khethelo Richman Xulu
- Department of Physiology, School of Laboratory Medicine and Medical Sciences, University of Kwa-Zulu Natal, Durban 4001, South Africa; (K.B.S.); (F.O.O.); (T.M.)
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5
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The "missing heritability"-Problem in psychiatry: Is the interaction of genetics, epigenetics and transposable elements a potential solution? Neurosci Biobehav Rev 2021; 126:23-42. [PMID: 33757815 DOI: 10.1016/j.neubiorev.2021.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/15/2021] [Accepted: 03/17/2021] [Indexed: 02/07/2023]
Abstract
Psychiatric disorders exhibit an enormous burden on the health care systems worldwide accounting for around one-third of years lost due to disability among adults. Their etiology is largely unknown and diagnostic classification is based on symptomatology and course of illness and not on objective biomarkers. Most psychiatric disorders are moderately to highly heritable. However, it is still unknown what mechanisms may explain the discrepancy between heritability estimates and the present data from genetic analysis. In addition to genetic differences also epigenetic modifications are considered as potentially relevant in the transfer of susceptibility to psychiatric diseases. Though, whether or not epigenetic alterations can be inherited for many generations is highly controversial. In the present article, we will critically summarize both the genetic findings and the results from epigenetic analyses, including also those of noncoding RNAs. We will argue that one possible solution to the "missing heritability" problem in psychiatry is a potential role of retrotransposons, the exploration of which is presently only in its beginnings.
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Nie FY, Zhang MR, Shang SS, Zhang QX, Zhang R, Chen P, Ma J. Methylome-wide association study of first-episode schizophrenia reveals a hypermethylated CpG site in the promoter region of the TNIK susceptibility gene. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110081. [PMID: 32853717 DOI: 10.1016/j.pnpbp.2020.110081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 12/11/2022]
Abstract
Accumulating evidence suggests that epigenetics plays an important role in the etiology of schizophrenia. Here, we performed a methylome-wide association study (MWAS) of first-onset schizophrenia patients and controls from the Han Chinese population using microarray technology. The DNA methylation profiles revealed 4494 differentially methylated CpG sites. Gene ontology (GO) analysis showed that the functions of differentially methylated genes were primarily involved in enzymatic activity, cytoskeleton organization and cell adhesion, and the TNIK (encoding TRAF2- and NCK-interacting kinase) gene was enriched in most of these terms. By combining the MWAS results with those of previous genome-wide association studies (GWASs), we identified 72 candidate genes located in 49 human genome loci. Among the overlapping genes, the most significantly methylated CpG sites were in the transcriptional start site (TSS) 200 region (cg21413905, Punadjusted = 3.20 × 10-5) of TNIK. TNIK was listed in the top 50 differentially methylated loci. The results of pyrosequencing and TNIK mRNA expression were consistent with those of the microarray study. Bioinformatics analyses, dual-luciferase reporter assays and chromatin immunoprecipitation (ChIP) studies showed that TNIK interacted with genes associated with schizophrenia and NRF1 was identified as a novel transcription factor (TF) that binds to TNIK in its TSS200 region. Thus, the regulatory function of NRF1 may be influenced by the status of the methylated CpG site in this region. In summary, our study provides new insights into the epigenetic mechanisms that regulate schizophrenia. Studies of the functions of TNIK methylation should be performed in vitro and in vivo to provide a better understanding of the pathophysiology of schizophrenia.
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Affiliation(s)
- Fa-Yi Nie
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Medical Research Center, Xi'an No.3 Hospital, Xi'an, Shaanxi 710018, China
| | - Miao-Ran Zhang
- Department of Genetics, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, China
| | - Shan-Shan Shang
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Qiao-Xia Zhang
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Rui Zhang
- Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China
| | - Peng Chen
- Department of Genetics, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, China.
| | - Jie Ma
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Medical Research Center, Xi'an No.3 Hospital, Xi'an, Shaanxi 710018, China.
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7
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Richetto J, Meyer U. Epigenetic Modifications in Schizophrenia and Related Disorders: Molecular Scars of Environmental Exposures and Source of Phenotypic Variability. Biol Psychiatry 2021; 89:215-226. [PMID: 32381277 DOI: 10.1016/j.biopsych.2020.03.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/19/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
Epigenetic modifications are increasingly recognized to play a role in the etiology and pathophysiology of schizophrenia and other psychiatric disorders with developmental origins. Here, we summarize clinical and preclinical findings of epigenetic alterations in schizophrenia and relevant disease models and discuss their putative origin. Recent findings suggest that certain schizophrenia risk loci can influence stochastic variation in gene expression through epigenetic processes, highlighting the intricate interaction between genetic and epigenetic control of neurodevelopmental trajectories. In addition, a substantial portion of epigenetic alterations in schizophrenia and related disorders may be acquired through environmental factors and may be manifested as molecular "scars." Some of these scars can influence brain functions throughout the entire lifespan and may even be transmitted across generations via epigenetic germline inheritance. Epigenetic modifications, whether caused by genetic or environmental factors, are plausible molecular sources of phenotypic heterogeneity and offer a target for therapeutic interventions. The further elucidation of epigenetic modifications thus may increase our knowledge regarding schizophrenia's heterogeneous etiology and pathophysiology and, in the long term, may advance personalized treatments through the use of biomarker-guided epigenetic interventions.
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Affiliation(s)
- Juliet Richetto
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, and Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
| | - Urs Meyer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, and Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
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Epigenomic Dysregulation in Schizophrenia: In Search of Disease Etiology and Biomarkers. Cells 2020; 9:cells9081837. [PMID: 32764320 PMCID: PMC7463953 DOI: 10.3390/cells9081837] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/27/2020] [Accepted: 07/31/2020] [Indexed: 12/13/2022] Open
Abstract
Schizophrenia is a severe psychiatric disorder with a complex array of signs and symptoms that causes very significant disability in young people. While schizophrenia has a strong genetic component, with heritability around 80%, there is also a very significant range of environmental exposures and stressors that have been implicated in disease development and neuropathology, such as maternal immune infection, obstetric complications, childhood trauma and cannabis exposure. It is postulated that epigenetic factors, as well as regulatory non-coding RNAs, mediate the effects of these environmental stressors. In this review, we explore the most well-known epigenetic marks, including DNA methylation and histone modification, along with emerging RNA mediators of epigenomic state, including miRNAs and lncRNAs, and discuss their collective potential for involvement in the pathophysiology of schizophrenia implicated through the postmortem analysis of brain tissue. Given that peripheral tissues, such as blood, saliva, and olfactory epithelium have the same genetic composition and are exposed to many of the same environmental exposures, we also examine some studies supporting the application of peripheral tissues for epigenomic biomarker discovery in schizophrenia. Finally, we provide some perspective on how these biomarkers may be utilized to capture a signature of past events that informs future treatment.
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Smigielski L, Jagannath V, Rössler W, Walitza S, Grünblatt E. Epigenetic mechanisms in schizophrenia and other psychotic disorders: a systematic review of empirical human findings. Mol Psychiatry 2020; 25:1718-1748. [PMID: 31907379 DOI: 10.1038/s41380-019-0601-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 12/26/2022]
Abstract
Schizophrenia and other psychotic disorders are highly debilitating psychiatric conditions that lack a clear etiology and exhibit polygenic inheritance underlain by pleiotropic genes. The prevailing explanation points to the interplay between predisposing genes and environmental exposure. Accumulated evidence suggests that epigenetic regulation of the genome may mediate dynamic gene-environment interactions at the molecular level by modulating the expression of psychiatric phenotypes through transcription factors. This systematic review summarizes the current knowledge linking schizophrenia and other psychotic disorders to epigenetics, based on PubMed and Web of Science database searches conducted according to the PRISMA guidelines. Three groups of mechanisms in case-control studies of human tissue (i.e., postmortem brain and bio-fluids) were considered: DNA methylation, histone modifications, and non-coding miRNAs. From the initial pool of 3,204 records, 152 studies met our inclusion criteria (11,815/11,528, 233/219, and 2,091/1,827 cases/controls for each group, respectively). Many of the findings revealed associations with epigenetic modulations of genes regulating neurotransmission, neurodevelopment, and immune function, as well as differential miRNA expression (e.g., upregulated miR-34a, miR-7, and miR-181b). Overall, actual evidence moderately supports an association between epigenetics and schizophrenia and other psychotic disorders. However, heterogeneous results and cross-tissue extrapolations call for future work. Integrating epigenetics into systems biology may critically enhance research on psychosis and thus our understanding of the disorder. This may have implications for psychiatry in risk stratification, early recognition, diagnostics, precision medicine, and other interventional approaches targeting epigenetic fingerprints.
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Affiliation(s)
- Lukasz Smigielski
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland. .,The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.
| | - Vinita Jagannath
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Merck Sharp & Dohme (MSD) R&D Innovation Centre, London, UK
| | - Wulf Rössler
- The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, University of Zurich, Zurich, Switzerland.,Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin, Berlin, Germany.,Laboratory of Neuroscience, Institute of Psychiatry, Universidade de São Paulo, São Paulo, Brazil
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,The Zurich Program for Sustainable Development of Mental Health Services (ZInEP), University Hospital of Psychiatry Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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10
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Ho NF, Tng JXJ, Wang M, Chen G, Subbaraju V, Shukor S, Ng DSX, Tan BL, Puang SJ, Kho SH, Siew RWE, Sin GL, Eu PW, Zhou J, Sng JCG, Sim K, Medalia A. Plasticity of DNA methylation, functional brain connectivity and efficiency in cognitive remediation for schizophrenia. J Psychiatr Res 2020; 126:122-133. [PMID: 32317108 DOI: 10.1016/j.jpsychires.2020.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 11/24/2022]
Abstract
Cognitive remediation (CR) is predicated on principles of neuroplasticity, but the actual molecular and neurocircuitry changes underlying cognitive change in individuals with impaired neuroplastic processes is poorly understood. The present study examined epigenetic-neurocircuitry-behavioral outcome measures in schizophrenia, before and after participating in a CR program that targeted higher-order cognitive functions. Outcome measures included DNA methylation of genes central to synaptic plasticity (CpG sites of Reelin promoter and BDNF promoter) from buccal swabs, resting-state functional brain connectivity and topological network efficiency, and global scores of a cognitive battery from 35 inpatients in a rehabilitative ward (18 CR, 17 non-CR) with similar premorbid IQ to 15 healthy controls. Baseline group differences between healthy controls and schizophrenia, group-by-time effects of CR in schizophrenia, and associations between the outcome measures were tested. Baseline functional connectivity abnormalities within the frontal, fronto-temporal and fronto-parietal regions, and trending decreases in global efficiency, but not DNA methylation, were found in schizophrenia; the frontal and fronto-temporal connectivity, and global efficiency correlated with global cognitive performance across all individuals. Notably, CR resulted in differential changes in Reelin promoter CpG methylation levels, altered within-frontal and fronto-temporal functional connectivity, increasing global efficiency and improving cognitive performance in schizophrenia, when compared to non-CR. In the CR inpatients, positive associations between the micro to macro measures: Reelin methylation changes, higher global efficiency and improving global cognitive performance were found. Present findings provide a neurobiological insight into potential CR-led epigenetics-neurocircuitry modifications driving cognitive plasticity.
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Affiliation(s)
- New Fei Ho
- Institute of Mental Health, Singapore; Duke-National University of Singapore Medical School, Singapore.
| | | | | | | | | | | | | | - Bhing-Leet Tan
- Institute of Mental Health, Singapore; Singapore Institute of Technology, Singapore
| | - Shu Juan Puang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Sok-Hong Kho
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Rachel Wan En Siew
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | - Juan Zhou
- Duke-National University of Singapore Medical School, Singapore; Center for Sleep and Cognition, Cognitive Neuroscience, Yong Loo Lin School of Medicine, National University of Singapore, SIngapore
| | - Judy Chia Ghee Sng
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kang Sim
- Institute of Mental Health, Singapore
| | - Alice Medalia
- Columbia University College of Physicians and Surgeons, New York, USA
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11
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The clues in solving the mystery of major psychosis: The epigenetic basis of schizophrenia and bipolar disorder. Neurosci Biobehav Rev 2020; 113:51-61. [DOI: 10.1016/j.neubiorev.2020.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/19/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023]
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12
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Notaras MJ, Vivian B, Wilson C, van den Buuse M. Interaction of reelin and stress on immobility in the forced swim test but not dopamine-mediated locomotor hyperactivity or prepulse inhibition disruption: Relevance to psychotic and mood disorders. Schizophr Res 2020; 215:485-492. [PMID: 28711473 DOI: 10.1016/j.schres.2017.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/28/2022]
Abstract
RATIONALE Psychotic disorders, such as schizophrenia, as well as some mood disorders, such as bipolar disorder, have been suggested to share common biological risk factors. One such factor is reelin, a large extracellular matrix glycoprotein that regulates neuronal migration during development as well as numerous activity-dependent processes in the adult brain. The current study sought to evaluate whether a history of stress exposure interacts with endogenous reelin levels to modify behavioural endophenotypes of relevance to psychotic and mood disorders. METHODS Heterozygous Reeler Mice (HRM) and wildtype (WT) controls were treated with 50mg/L of corticosterone (CORT) in their drinking water from 6 to 9weeks of age, before undergoing behavioural testing in adulthood. We assessed methamphetamine-induced locomotor hyperactivity, prepulse inhibition (PPI) of acoustic startle, short-term spatial memory in the Y-maze, and depression-like behaviour in the Forced-Swim Test (FST). RESULTS HRM genotype or CORT treatment did not affect methamphetamine-induced locomotor hyperactivity, a model of psychosis-like behaviour. At baseline, HRM showed decreased PPI at the commonly used 100msec interstimulus interval (ISI), but not at the 30msec ISI or following challenge with apomorphine. A history of CORT exposure potentiated immobility in the FST amongst HRM, but not WT mice. In the Y-maze, chronic CORT treatment decreased novel arm preference amongst HRM, reflecting reduced short-term spatial memory. CONCLUSION These data confirm a significant role of endogenous reelin levels on stress-related behaviour, supporting a possible role in both bipolar disorder and schizophrenia. However, an interaction of reelin deficiency with dopaminergic regulation of psychosis-like behaviour remains unclear.
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Affiliation(s)
- Michael J Notaras
- Florey Institute of Neuroscience & Mental Health, Melbourne, Victoria, Australia
| | - Billie Vivian
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Carey Wilson
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Maarten van den Buuse
- School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia; Department of Pharmacology, University of Melbourne, Victoria, Australia; The College of Public Health, Medical and Veterinary Sciences, James Cook University, Queensland, Australia.
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13
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Wani AL, Shadab GHA. Brain, behavior and the journey towards neuroepigenetic therapeutics. Epigenomics 2019; 11:969-981. [PMID: 31144515 DOI: 10.2217/epi-2018-0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Epigenetics has brought about a major shift in our understanding of biological mechanisms and their associated health effects. Strong epigenetic components have been found to be involved in the progression of many diseases. In several human diseases, including debilitating psychiatric disorders, altered epigenetic status has been found as one of the main causes. With continuous progress on drug development, researchers are enthusiastic toward epigenetic therapeutics which could possibly reverse epigenetic modifications. In this article certain developments in epigenetic therapeutics are highlighted, the indiscriminate use of which could also be associated with potential risk. These risks may partly be due to our limited knowledge on genes and the mechanisms underlying epigenetic involvement in different diseases. Epigenetic changes are fundamentally important for a large number of bodily functions; nonspecific usage of therapeutics could be potentially harmful therefore there is a need to harness epigenetics positively.
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Affiliation(s)
- Ab Latif Wani
- Cytogenetics & Molecular Toxicology Laboratory, Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
| | - Gg Hammad Ahmad Shadab
- Cytogenetics & Molecular Toxicology Laboratory, Section of Genetics, Department of Zoology, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
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Alfimova MV, Kondratiev NV, Golov AK, Golimbet VE. Methylation of the Reelin Gene Promoter in Peripheral Blood and Its Relationship with the Cognitive Function of Schizophrenia Patients. Mol Biol 2018. [DOI: 10.1134/s0026893318050023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Mohammadi A, Rashidi E, Amooeian VG. Brain, blood, cerebrospinal fluid, and serum biomarkers in schizophrenia. Psychiatry Res 2018; 265:25-38. [PMID: 29680514 DOI: 10.1016/j.psychres.2018.04.036] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/20/2018] [Accepted: 04/11/2018] [Indexed: 12/29/2022]
Abstract
Over the last decade, finding a reliable biomarker for the early detection of schizophrenia (Scz) has been a topic of interest. The main goal of the current review is to provide a comprehensive view of the brain, blood, cerebrospinal fluid (CSF), and serum biomarkers of Scz disease. Imaging studies have demonstrated that the volumes of the corpus callosum, thalamus, hippocampal formation, subiculum, parahippocampal gyrus, superior temporal gyrus, prefrontal and orbitofrontal cortices, and amygdala-hippocampal complex were reduced in patients diagnosed with Scz. It has been revealed that the levels of interleukin 1β (IL-1β), IL-6, IL-8, and TNF-α were increased in patients with Scz. Decreased mRNA levels of brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), neurotrophin-3 (NT-3), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) genes have also been reported in Scz patients. Genes with known strong relationships with this disease include BDNF, catechol-O-methyltransferase (COMT), regulator of G-protein signaling 4 (RGS4), dystrobrevin-binding protein 1 (DTNBP1), neuregulin 1 (NRG1), Reelin (RELN), Selenium-binding protein 1 (SELENBP1), glutamic acid decarboxylase 67 (GAD 67), and disrupted in schizophrenia 1 (DISC1). The levels of dopamine, tyrosine hydroxylase (TH), serotonin or 5-hydroxytryptamine (5-HT) receptor 1A and B (5-HTR1A and 5-HTR1B), and 5-HT1B were significantly increased in Scz patients, while the levels of gamma-aminobutyric acid (GABA), 5-HT transporter (5-HTT), and 5-HT receptor 2A (5-HTR2A) were decreased. The increased levels of SELENBP1 and Glycogen synthase kinase 3 subunit α (GSK3α) genes in contrast with reduced levels of B-cell translocation gene 1 (BTG1), human leukocyte antigen DRB1 (HLA-DRB1), heterogeneous nuclear ribonucleoprotein A3 (HNRPA3), and serine/arginine-rich splicing factor 1 (SFRS1) genes have also been reported. This review covers various dysregulation of neurotransmitters and also highlights the strengths and weaknesses of studies attempting to identify candidate biomarkers.
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Affiliation(s)
- Alireza Mohammadi
- Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - Ehsan Rashidi
- Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran
| | - Vahid Ghasem Amooeian
- Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran
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Liu C, Jiao C, Wang K, Yuan N. DNA Methylation and Psychiatric Disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 157:175-232. [PMID: 29933950 DOI: 10.1016/bs.pmbts.2018.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
DNA methylation has been an important area of research in the study of molecular mechanism to psychiatric disorders. Recent evidence has suggested that abnormalities in global methylation, methylation of genes, and pathways could play a role in the etiology of many forms of mental illness. In this article, we review the mechanisms of DNA methylation, including the genetic and environmental factors affecting methylation changes. We report and discuss major findings regarding DNA methylation in psychiatric patients, both within the context of global methylation studies and gene-specific methylation studies. Finally, we discuss issues surrounding data quality improvement, the limitations of current methylation analysis methods, and the possibility of using DNA methylation-based treatment for psychiatric disorders in the future.
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Affiliation(s)
- Chunyu Liu
- University of Illinois, Chicago, IL, United States; School of Life Science, Central South University, Changsha, China.
| | - Chuan Jiao
- School of Life Science, Central South University, Changsha, China
| | - Kangli Wang
- School of Life Science, Central South University, Changsha, China
| | - Ning Yuan
- Hunan Brain Hospital, Changsha, China
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Mata‐Balaguer T, Cuchillo‐Ibañez I, Calero M, Ferrer I, Sáez‐Valero J. Decreased generation of C‐terminal fragments of ApoER2 and increased reelin expression in Alzheimer's disease. FASEB J 2018; 32:3536-3546. [DOI: 10.1096/fj.201700736rr] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Trinidad Mata‐Balaguer
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Cientificas (CSIC)Sant Joan d'AlacantAlicanteSpain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)MadridSpain
| | - Inmaculada Cuchillo‐Ibañez
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Cientificas (CSIC)Sant Joan d'AlacantAlicanteSpain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)MadridSpain
| | - Miguel Calero
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)MadridSpain
- Alzheimer Disease Research UnitCentro Nacional de Investigación en Enfermedades Neurológicas (CIEN) FoundationQueen Sofia Foundation Alzheimer CenterMadridSpain
- Chronic Disease ProgrammeCarlos III Institute of HealthMadridSpain
| | - Isidro Ferrer
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)MadridSpain
- Instituto de NeuropatologíaHospital Universitario de BellvitgeUniversidad de BarcelonaHospitalet de LlobregatBarcelonaSpain
| | - Javier Sáez‐Valero
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Cientificas (CSIC)Sant Joan d'AlacantAlicanteSpain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)MadridSpain
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Nabil Fikri RM, Norlelawati AT, Nour El-Huda AR, Hanisah MN, Kartini A, Norsidah K, Nor Zamzila A. Reelin (RELN) DNA methylation in the peripheral blood of schizophrenia. J Psychiatr Res 2017; 88:28-37. [PMID: 28086126 DOI: 10.1016/j.jpsychires.2016.12.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/28/2016] [Accepted: 12/31/2016] [Indexed: 01/08/2023]
Abstract
The epigenetic changes of RELN that are involved in the development of dopaminergic neurons may fit the developmental theory of schizophrenia. However, evidence regarding the association of RELN DNA methylation with schizophrenia is far from sufficient, as studies have only been conducted on a few limited brain samples. As DNA methylation in the peripheral blood may mirror the changes taking place in the brain, the use of peripheral blood for a DNA methylation study in schizophrenia is feasible due to the scarcity of brain samples. Therefore, the aim of our study was to examine the relationship of DNA methylation levels of RELN promoters with schizophrenia using genomic DNA derived from the peripheral blood of patients with the disorder. The case control studies consisted of 110 schizophrenia participants and 122 healthy controls who had been recruited from the same district. After bisufhite conversion, the methylation levels of the DNA samples were calculated based on their differences of the Cq values assayed using the highly sensitive real-time MethyLight TaqMan® procedure. A significantly higher level of methylation of the RELN promoter was found in patients with schizophrenia compared to controls (p = 0.005) and also in males compared with females (p = 0.004). Subsequently, the RELN expression of the methylated group was 25 fold less than that of the non-methylated group. Based upon the assumption of parallel methylation changes in the brain and peripheral blood, we concluded that RELN DNA methylation might contribute to the pathogenesis of schizophrenia. However, the definite effects of methylation on RELN function during development and also in adult life still require further elaboration.
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Affiliation(s)
- Rahim Mohd Nabil Fikri
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
| | - A Talib Norlelawati
- Department of Pathology & Laboratory Medicine, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia.
| | - Abdul Rahim Nour El-Huda
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
| | - Mohd Noor Hanisah
- Department of Psychiatry, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
| | - Abdullah Kartini
- Department of Psychiatry, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
| | - Kuzaifah Norsidah
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
| | - Abdullah Nor Zamzila
- Department of Pathology & Laboratory Medicine, Kulliyyah of Medicine, International Islamic University Malaysia, Malaysia
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Swathy B, Banerjee M. Understanding epigenetics of schizophrenia in the backdrop of its antipsychotic drug therapy. Epigenomics 2017; 9:721-736. [DOI: 10.2217/epi-2016-0106] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The diatheses of gene and environment interaction in schizophrenia (SCZ) are becoming increasingly evident. Genetic and epigenetic backgrounds are being considered in stratifying and addressing phenotypic variation and drug response in SCZ. But how much of these epigenetic alterations are the primary contributing factor, toward disease pathogenesis and drug response, needs further clarity. Evidence indicates that antipsychotic drugs can also alter the epigenetic homeostasis thereby inducing pharmacoepigenomic effects. We re-examine the context of epigenetics in disease pathogenesis and antipsychotic drug therapy in SCZ to understand how much of these observations act as real indicators of the disease or therapeutic response. We propose that epigenetic viewpoint in SCZ needs to be critically examined under the genetic, epigenetic and pharmacoepigenetic background.
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Affiliation(s)
- Babu Swathy
- Human Molecular Genetics Laboratory, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
| | - Moinak Banerjee
- Human Molecular Genetics Laboratory, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
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20
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Abstract
Schizophrenia is a highly heritable psychiatric condition that displays a complex phenotype. A multitude of genetic susceptibility loci have now been identified, but these fail to explain the high heritability estimates of schizophrenia. In addition, epidemiologically relevant environmental risk factors for schizophrenia may lead to permanent changes in brain function. In conjunction with genetic liability, these environmental risk factors-likely through epigenetic mechanisms-may give rise to schizophrenia, a clinical syndrome characterized by florid psychotic symptoms and moderate to severe cognitive impairment. These pathophysiological features point to the involvement of epigenetic processes. Recently, a wave of studies examining aberrant DNA modifications in schizophrenia was published. This chapter aims to comprehensively review the current findings, from both candidate gene studies and genome-wide approaches, on DNA methylation changes in schizophrenia.
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21
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Ishii K, Kubo KI, Nakajima K. Reelin and Neuropsychiatric Disorders. Front Cell Neurosci 2016; 10:229. [PMID: 27803648 PMCID: PMC5067484 DOI: 10.3389/fncel.2016.00229] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/22/2016] [Indexed: 12/22/2022] Open
Abstract
Proper neuronal migration and laminar formation during corticogenesis is essential for normal brain function. Disruption of these developmental processes is thought to be involved in the pathogenesis of some neuropsychiatric conditions. Especially, Reelin, a glycoprotein mainly secreted by the Cajal-Retzius cells and a subpopulation of GABAergic interneurons, has been shown to play a critical role, both during embryonic and postnatal periods. Indeed, animal studies have clearly revealed that Reelin is an essential molecule for proper migration of cortical neurons and finally regulates the cell positioning in the cortex during embryonic and early postnatal stages; by contrast, Reelin signaling is closely involved in synaptic function in adulthood. In humans, genetic studies have shown that the reelin gene (RELN) is associated with a number of psychiatric diseases, including Schizophrenia (SZ), bipolar disorder (BP) and autistic spectrum disorder. Indeed, Reln haploinsufficiency has been shown to cause cognitive impairment in rodents, suggesting the expression level of the Reelin protein is closely related to the higher brain functions. However, the molecular abnormalities in the Reelin pathway involved in the pathogenesis of psychiatric disorders are not yet fully understood. In this article, we review the current progress in the understanding of the Reelin functions that could be related to the pathogenesis of psychiatric disorders. Furthermore, we discuss the basis for selecting Reelin and molecules in its downstream signaling pathway as potential therapeutic targets for psychiatric illnesses.
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Affiliation(s)
- Kazuhiro Ishii
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
| | - Ken-Ichiro Kubo
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
| | - Kazunori Nakajima
- Department of Anatomy, Keio University School of Medicine Tokyo, Japan
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Cariaga-Martinez A, Saiz-Ruiz J, Alelú-Paz R. From Linkage Studies to Epigenetics: What We Know and What We Need to Know in the Neurobiology of Schizophrenia. Front Neurosci 2016; 10:202. [PMID: 27242407 PMCID: PMC4862989 DOI: 10.3389/fnins.2016.00202] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 04/25/2016] [Indexed: 01/15/2023] Open
Abstract
Schizophrenia is a complex psychiatric disorder characterized by the presence of positive, negative, and cognitive symptoms that lacks a unifying neuropathology. In the present paper, we will review the current understanding of molecular dysregulation in schizophrenia, including genetic and epigenetic studies. In relation to the latter, basic research suggests that normal cognition is regulated by epigenetic mechanisms and its dysfunction occurs upon epigenetic misregulation, providing new insights into missing heritability of complex psychiatric diseases, referring to the discrepancy between epidemiological heritability and the proportion of phenotypic variation explained by DNA sequence difference. In schizophrenia the absence of consistently replicated genetic effects together with evidence for lasting changes in gene expression after environmental exposures suggest a role of epigenetic mechanisms. In this review we will focus on epigenetic modifications as a key mechanism through which environmental factors interact with individual's genetic constitution to affect risk of psychotic conditions throughout life.
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Affiliation(s)
- Ariel Cariaga-Martinez
- Laboratory for Neuroscience of Mental Disorders Elena Pessino, Department of Medicine and Medical Specialties, School of Medicine, Alcalá University Madrid, Spain
| | - Jerónimo Saiz-Ruiz
- Department of Psychiatry, Ramón y Cajal Hospital, IRYCISMadrid, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM)Madrid, Spain
| | - Raúl Alelú-Paz
- Laboratory for Neuroscience of Mental Disorders Elena Pessino, Department of Medicine and Medical Specialties, School of Medicine, Alcalá UniversityMadrid, Spain; Department of Psychiatry, Ramón y Cajal Hospital, IRYCISMadrid, Spain
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Guidotti A, Grayson DR, Caruncho HJ. Epigenetic RELN Dysfunction in Schizophrenia and Related Neuropsychiatric Disorders. Front Cell Neurosci 2016; 10:89. [PMID: 27092053 PMCID: PMC4820443 DOI: 10.3389/fncel.2016.00089] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/21/2016] [Indexed: 01/02/2023] Open
Abstract
REELIN (RELN) is a large (420 kDa) glycoprotein that in adulthood is mostly synthesized in GABAergic neurons of corticolimbic structures. Upon secretion in the extracellular matrix (ECM), RELN binds to VLDL, APOE2, and α3β2 Integrin receptors located on dendritic shafts and spines of postsynaptic pyramidal neurons. Reduced levels of RELN expression in the adult brain induce cognitive impairment and dendritic spine density deficits. RELN supplementation recovers these deficits suggesting a trophic action for RELN in synaptic plasticity. We and others have shown that altered RELN expression in schizophrenia (SZ) and bipolar (BP) disorder patients is difficult to reconcile with classical Mendelian genetic disorders and it is instead plausible to associate these disorders with altered epigenetic homeostasis. Support for the contribution of altered epigenetic mechanisms in the down-regulation of RELN expression in corticolimbic structures of psychotic patients includes the concomitant increase of DNA-methyltransferases and the increased levels of the methyl donor S-adenosylmethionine (SAM). It is hypothesized that these conditions lead to RELN promoter hypermethylation and a reduction in RELN protein amounts in psychotic patients. The decreased synthesis and release of RELN from GABAergic corticolimbic neurons could serve as a model to elucidate the epigenetic pathophysiological mechanisms acting at pyramidal neuron dendrites that regulate synaptic plasticity and cognition in psychotic and non-psychotic subjects.
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Affiliation(s)
- Alessandro Guidotti
- Department of Psychiatry, The Psychiatric Institute, College of Medicine, University of Illinois at Chicago Chicago, IL, USA
| | - Dennis R Grayson
- Department of Psychiatry, The Psychiatric Institute, College of Medicine, University of Illinois at Chicago Chicago, IL, USA
| | - Hector J Caruncho
- College of Pharmacy and Nutrition, University of Saskatchewan Saskatoon, SK, Canada
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Negrón-Oyarzo I, Lara-Vásquez A, Palacios-García I, Fuentealba P, Aboitiz F. Schizophrenia and reelin: a model based on prenatal stress to study epigenetics, brain development and behavior. Biol Res 2016; 49:16. [PMID: 26968981 PMCID: PMC4787713 DOI: 10.1186/s40659-016-0076-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/22/2016] [Indexed: 11/20/2022] Open
Abstract
Schizophrenia is a severe psychiatric disorder that results in a significant disability for the patient. The disorder is characterized by impairment of the adaptive orchestration of actions, a cognitive function that is mainly dependent on the prefrontal cortex. This behavioral deficit, together with cellular and neurophysiological alterations in the prefrontal cortex, as well as reduced density of GABAergic cells and aberrant oscillatory activity, all indicate structural and functional deficits of the prefrontal cortex in schizophrenia. Among the several risk factors for the development of schizophrenia, stress during the prenatal period has been identified as crucial. Thus, it is proposed that prenatal stress induces neurodevelopmental alterations in the prefrontal cortex that are expressed as cognitive impairment observed in schizophrenia. However, the precise mechanisms that link prenatal stress with the impairment of prefrontal cortex function is largely unknown. Reelin is an extracellular matrix protein involved in the development of cortical neural connectivity at embryonic stages, and in synaptic plasticity at postnatal stages. Interestingly, down-regulation of reelin expression has been associated with epigenetic changes in the reelin gene of the prefrontal cortex of schizophrenic patients. We recently showed that, similar to schizophrenic patients, prenatal stress induces down-expression of reelin associated with the methylation of its promoter in the rodent prefrontal cortex. These alterations were paralleled with altered prefrontal cortex functional connectivity and impairment in prefrontal cortex-dependent behavioral tasks. Therefore, considering molecular, cellular, physiological and behavioral evidence, we propose a unifying framework that links prenatal stress and prefrontal malfunction through epigenetic alterations of the reelin gene.
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Affiliation(s)
- Ignacio Negrón-Oyarzo
- Departamento de Psiquiatría, Escuela de Medicina, and Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ariel Lara-Vásquez
- Departamento de Psiquiatría, Escuela de Medicina, and Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ismael Palacios-García
- Departamento de Psiquiatría, Escuela de Medicina, and Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Fuentealba
- Departamento de Psiquiatría, Escuela de Medicina, and Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Francisco Aboitiz
- Departamento de Psiquiatría, Escuela de Medicina, and Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de Chile, Santiago, Chile
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Çöpoğlu ÜS, Igci M, Bozgeyik E, Kokaçya MH, İğci YZ, Dokuyucu R, Ari M, Savaş HA. DNA Methylation of BDNF Gene in Schizophrenia. Med Sci Monit 2016; 22:397-402. [PMID: 26851233 PMCID: PMC4749043 DOI: 10.12659/msm.895896] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background Although genetic factors are risk factors for schizophrenia, some environmental factors are thought to be required for the manifestation of disease. Epigenetic mechanisms regulate gene functions without causing a change in the nucleotide sequence of DNA. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that regulates synaptic transmission and plasticity. It has been suggested that BDNF may play a role in the pathophysiology of schizophrenia. It is established that methylation status of the BDNF gene is associated with fear learning, memory, and stressful social interactions. In this study, we aimed to investigate the DNA methylation status of BDNF gene in patients with schizophrenia. Material/Methods The study included 49 patients (33 male and 16 female) with schizophrenia and 65 unrelated healthy controls (46 male and 19 female). Determination of methylation pattern of CpG islands was based on the principle that bisulfite treatment of DNA results in conversion of unmethylated cytosine residues into uracil, whereas methylated cytosine residues remain unmodified. Methylation-specific PCR was performed with primers specific for either methylated or unmethylated DNA. Results There was no significant difference in methylated or un-methylated status for BDNF promoters between schizophrenia patients and controls. The mean duration of illness was significantly lower in the hemi-methylated group compared to the non-methylated group for BDNF gene CpG island-1 in schizophrenia patients. Conclusions Although there were no differences in BDNF gene methylation status between schizophrenia patients and healthy controls, there was an association between duration of illness and DNA methylation.
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Affiliation(s)
- Ümit Sertan Çöpoğlu
- Department of Psychiatry, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Mehri Igci
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - Esra Bozgeyik
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - M Hanifi Kokaçya
- Department of Psychiatry, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Yusuf Ziya İğci
- Department Medical Biology, School of Medicine, Gaziantep University, Gaziantep, Turkey
| | - Recep Dokuyucu
- Department of Physiology, School of Medicine, Mustafa Kemal University, Hatay, Turkey
| | - Mustafa Ari
- Department of Physiology, Mustafa Kemal University, School of Medicine, Hatay, Turkey
| | - Haluk A Savaş
- Department Psychiatry, School of Medicine, Gaziantep University, Gaziantep, Turkey
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Teroganova N, Girshkin L, Suter CM, Green MJ. DNA methylation in peripheral tissue of schizophrenia and bipolar disorder: a systematic review. BMC Genet 2016; 17:27. [PMID: 26809779 PMCID: PMC4727379 DOI: 10.1186/s12863-016-0332-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/13/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Increasing evidence suggests the involvement of epigenetic processes in the development of schizophrenia and bipolar disorder, and recent reviews have focused on findings in post-mortem brain tissue. A systematic review was conducted to synthesise and evaluate the quality of available evidence for epigenetic modifications (specifically DNA methylation) in peripheral blood and saliva samples of schizophrenia and bipolar disorder patients in comparison to healthy controls. METHODS Original research articles using humans were identified using electronic databases. There were 33 included studies for which data were extracted and graded in duplicate on 22 items of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement, to assess methodological precision and quality of reporting. RESULTS There were 15 genome-wide and 18 exclusive candidate gene loci investigations for DNA methylation studies. A number of common genes were identified as differentially methylated in schizophrenia/bipolar disorder, which were related to reelin, brain-derived neurotrophic factor, dopamine (including the catechol-O-methyltransferase gene), serotonin and glutamate, despite inconsistent findings of hyper-, hypo-, or lack of methylation at these and other loci. The mean STROBE score of 59% suggested moderate quality of available evidence; however, wide methodological variability contributed to a lack of consistency in the way methylation levels were quantified, such that meta-analysis of the results was not possible. CONCLUSIONS Moderate quality of available evidence shows some convergence of differential methylation at some common genetic loci in schizophrenia and bipolar disorder, despite wide variation in methodology and reporting across studies. Improvement in the clarity of reporting clinical and other potential confounds would be useful in future studies of epigenetic processes in the context of exposure to environmental and other risk factors.
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Affiliation(s)
- Nina Teroganova
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia.
- Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW, 2010, Australia.
| | - Leah Girshkin
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia.
- Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW, 2010, Australia.
| | - Catherine M Suter
- Molecular Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia.
| | - Melissa J Green
- School of Psychiatry, University of New South Wales, Randwick, NSW, Australia.
- Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW, 2010, Australia.
- Neuroscience Research Australia, Sydney, NSW, 2031, Australia.
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Ayhan Y, McFarland R, Pletnikov MV. Animal models of gene-environment interaction in schizophrenia: A dimensional perspective. Prog Neurobiol 2015; 136:1-27. [PMID: 26510407 DOI: 10.1016/j.pneurobio.2015.10.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 09/07/2015] [Accepted: 10/22/2015] [Indexed: 12/12/2022]
Abstract
Schizophrenia has long been considered as a disorder with multifactorial origins. Recent discoveries have advanced our understanding of the genetic architecture of the disease. However, even with the increase of identified risk variants, heritability estimates suggest an important contribution of non-genetic factors. Various environmental risk factors have been proposed to play a role in the etiopathogenesis of schizophrenia. These include season of birth, maternal infections, obstetric complications, adverse events at early childhood, and drug abuse. Despite the progress in identification of genetic and environmental risk factors, we still have a limited understanding of the mechanisms whereby gene-environment interactions (G × E) operate in schizophrenia and psychoses at large. In this review we provide a critical analysis of current animal models of G × E relevant to psychotic disorders and propose that dimensional perspective will advance our understanding of the complex mechanisms of these disorders.
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Affiliation(s)
- Yavuz Ayhan
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Hacettepe University Faculty of Medicine, Department of Psychiatry, Turkey
| | - Ross McFarland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, USA
| | - Mikhail V Pletnikov
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, USA; Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, USA.
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Abstract
Histone modifications and DNA methylation represent central dynamic and reversible processes that regulate gene expression and contribute to cellular phenotypes. These epigenetic marks have been shown to play fundamental roles in a diverse set of signaling and behavioral outcomes. Psychiatric disorders such as schizophrenia and depression are complex and heterogeneous diseases with multiple and independent factors that may contribute to their pathophysiology, making challenging to find a link between specific elements and the underlying mechanisms responsible for the disorder and its treatment. Growing evidences suggest that epigenetic modifications in certain brain regions and neural circuits represent a key mechanism through which environmental factors interact with individual's genetic constitution to affect risk of psychiatric conditions throughout life. This review focuses on recent advances that directly implicate epigenetic modifications in schizophrenia and antipsychotic drug action.
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Affiliation(s)
- Daisuke Ibi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Javier González-Maeso
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Physiology and Biophysics, Virginia Commonwealth University Medical School, Richmond, VA 23298, USA.
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Dong E, Ruzicka WB, Grayson D, Guidotti A. DNA-methyltransferase1 (DNMT1) binding to CpG rich GABAergic and BDNF promoters is increased in the brain of schizophrenia and bipolar disorder patients. Schizophr Res 2015; 167:35-41. [PMID: 25476119 PMCID: PMC4451449 DOI: 10.1016/j.schres.2014.10.030] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/16/2014] [Accepted: 10/19/2014] [Indexed: 10/24/2022]
Abstract
The down regulation of glutamic acid decarboxylase67 (GAD1), reelin (RELN), and BDNF expression in brain of schizophrenia (SZ) and bipolar (BP) disorder patients is associated with overexpression of DNA methyltransferase1 (DNMT1) and ten-eleven translocase methylcytosine dioxygenase1 (TET1). DNMT1 and TET1 belong to families of enzymes that methylate and hydroxymethylate cytosines located proximal to and within cytosine phosphodiester guanine (CpG) islands of many gene promoters, respectively. Altered promoter methylation may be one mechanism underlying the down-regulation of GABAergic and glutamatergic gene expression. However, recent reports suggest that both DNMT1 and TET1 directly bind to unmethylated CpG rich promoters through their respective Zinc Finger (ZF-CXXC) domains. We report here, that the binding of DNMT1 to GABAergic (GAD1, RELN) and glutamatergic (BDNF-IX) promoters is increased in SZ and BP disorder patients and this increase does not necessarily correlate with enrichment in promoter methylation. The increased DNMT1 binding to these promoter regions is detected in the cortex but not in the cerebellum of SZ and BP disorder patients, suggesting a brain region and neuron specific dependent mechanism. Increased binding of DNMT1 positively correlates with increased expression of DNMT1 and with increased binding of MBD2. In contrast, the binding of TET1 to RELN, GAD1 and BDNF-IX promoters failed to change. These data are consistent with the hypothesis that the down-regulation of specific GABAergic and glutamatergic genes in SZ and BP disorder patients may be mediated, at least in part, by a brain region specific and neuronal-activity dependent DNMT1 action that is likely independent of its DNA methylation activity.
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Affiliation(s)
- E. Dong
- Department of Psychiatry, College of Medicine, University of Illinois at Chicago
| | - W. B. Ruzicka
- Program in Structural and Molecular Neuroscience, McLean Hospital., Belmont, MA,Department of Psychiatry, Harvard Medical School, Boston, MA
| | - D.R. Grayson
- Department of Psychiatry, College of Medicine, University of Illinois at Chicago
| | - A. Guidotti
- Department of Psychiatry, College of Medicine, University of Illinois at Chicago,Corresponding author: A. Guidotti, 1601 W. Taylor St., Chicago, IL 60612, , 312-413-4594
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Guidotti A, Grayson DR. DNA methylation and demethylation as targets for antipsychotic therapy. DIALOGUES IN CLINICAL NEUROSCIENCE 2015. [PMID: 25364290 PMCID: PMC4214182 DOI: 10.31887/dcns.2014.16.3/aguidotti] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Schizophrenia (SZ) and bipolar disorder (BPD) patients show a downregulation of GAD67, reelin (RELN), brain-derived neurotrophic factor (BDNF), and other genes expressed in telencephalic GABAergic and glutamatergic neurons. This downregulation is associated with the enrichment of 5-methylcytosine and 5-hydroxymethylcytosine proximally at gene regulatory domains at the respective genes. A pharmacological strategy to reduce promoter hypermethylation and to induce a more permissive chromatin conformation is to administer drugs, such as the histone deacetylase (HDAC) inhibitor valproate (VPA), that facilitate chromatin remodeling. Studies in mouse models of SZ indicate that clozapine induces DNA demethylation at relevant promoters, and that this action is potentiated by VPA. By activating DNA demethylation, clozapine or its derivatives with VPA or other more potent and selective HDAC inhibitors may be a promising treatment strategy to correct the gene expression deficits detected in postmortem brain of SZ and BPD patients.
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Affiliation(s)
- Alessandro Guidotti
- Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Illinois, USA
| | - Dennis R Grayson
- Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Illinois, USA
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Alelú-Paz R, González-Corpas A, Ashour N, Escanilla A, Monje A, Guerrero Márquez C, Algora Weber M, Ropero S. DNA methylation pattern of gene promoters of major neurotransmitter systems in older patients with schizophrenia with severe and mild cognitive impairment. Int J Geriatr Psychiatry 2015; 30:558-65. [PMID: 25044034 DOI: 10.1002/gps.4182] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 06/27/2014] [Accepted: 07/02/2014] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To analyze, in older patients with schizophrenia, the methylation status of a set of genes associated with the pathophysiology of the disorder but including anatomical, clinical, and cognitive criteria in the experimental design that, in conjunction with the epigenetic status of specific genes, allows us to derive an integrative model. METHOD This study included 29 human brain samples from older schizophrenic patients with severe and mild cognitive impairment. We administered a comprehensive battery of neurocognitive tests to determine the size of the impairment across different cognitive domains. We focused our study on the analysis of the methylation pattern of 19 genes of major neurotransmitter systems using methylation-specific PCR and bisulfite genomic sequencing. RESULTS Our results highlight an absence of hypermethylation and hypomethylation in older patients with schizophrenia and in healthy controls, irrespective of the degree of the cognitive deficit measured in the neuropsychological assessment (Fisher's exact test; p<0.05). CONCLUSION mRNA or protein expression level differences in genes of major neurotransmitter systems that are known to be altered in schizophrenia must be because of regulatory mechanisms other than the DNA methylation of its promoter regions, although our results highlight the idea that the analysis of the epigenetic mechanisms involved in schizophrenia represents a new approach that has the possibility of uncovering molecular mechanisms of dysregulated gene expression in this complex disorder.
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Affiliation(s)
- Raúl Alelú-Paz
- Department of Medicine and Medical Specialities, School of Medicine, University of Alcalá, Madrid, Spain; Department of Physiology, Biochemistry and Molecular Biology, School of Medicine, University of Alcalá, Madrid, Spain
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Szyf M. Prospects for the development of epigenetic drugs for CNS conditions. Nat Rev Drug Discov 2015; 14:461-74. [DOI: 10.1038/nrd4580] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Zong X, Hu M, Li Z, Cao H, Chen X, Tang J. DNA methylation in schizophrenia: progress and challenges. Sci Bull (Beijing) 2015. [DOI: 10.1007/s11434-014-0690-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Schmidt MJ, Mirnics K. Neurodevelopment, GABA system dysfunction, and schizophrenia. Neuropsychopharmacology 2015; 40:190-206. [PMID: 24759129 PMCID: PMC4262918 DOI: 10.1038/npp.2014.95] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 04/03/2014] [Accepted: 04/11/2014] [Indexed: 02/07/2023]
Abstract
The origins of schizophrenia have eluded clinicians and researchers since Kraepelin and Bleuler began documenting their findings. However, large clinical research efforts in recent decades have identified numerous genetic and environmental risk factors for schizophrenia. The combined data strongly support the neurodevelopmental hypothesis of schizophrenia and underscore the importance of the common converging effects of diverse insults. In this review, we discuss the evidence that genetic and environmental risk factors that predispose to schizophrenia disrupt the development and normal functioning of the GABAergic system.
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Affiliation(s)
- Martin J Schmidt
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA
| | - Karoly Mirnics
- Department of Psychiatry, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN, USA
- Department of Psychiatry, University of Szeged, Szeged, Hungary
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Greenberg Z, Ramshaw H, Schwarz Q. Time Windows of Interneuron Development: Implications to Our Understanding of the Aetiology and Treatment of Schizophrenia. AIMS Neurosci 2015. [DOI: 10.3934/neuroscience.2015.4.294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
Epigenetics is the study of chromatin-the physical material that forms chromosomes, composed of DNA wound around specialized histone proteins-and of how the modification of chromatin acts to establish stable states of gene expression in a cell-specific manner. Chromatin is regulated through three mechanisms: DNA methylation, histone modification, and RNA interference. These basic biological processes form the molecular interface between the genome and the environment, contributing to the regulation of gene expression in health and disease. Investigation of epigenetic mechanisms is yielding exciting insights in many areas of medicine, and a large and rapidly growing literature describes epigenetics as central to many aspects of the pathophysiology of psychotic disorders. This article first discusses speculative points as to why the mechanisms of epigenetics may be satisfying explanatory mechanisms in the etiology of psychotic disorders, then details emerging experimental evidence of roles for the three types of epigenetic mechanisms in these illnesses, and finally discusses these mechanisms as potentially compelling areas of research for the development of future treatments.
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Bosia M, Pigoni A, Cavallaro R. Genomics and epigenomics in novel schizophrenia drug discovery: translating animal models to clinical research and back. Expert Opin Drug Discov 2014; 10:125-39. [PMID: 25345474 DOI: 10.1517/17460441.2015.976552] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Schizophrenia is a major psychiatric disorder that afflicts about 1% of the world's population, falling into the top 10 medical disorders causing disability. Existing therapeutic strategies have had limited success; they have poor effects on core cognitive impairment and long-term disability. They are also burdened by relevant side effects. Although new antipsychotic medications have been launched in the past decades, there has been a general lack of significant innovation over the past 60 years. This lack of significant progress in the pharmacotherapy of schizophrenia is a reflection of the complexity and heterogeneity of its etiopathogenetic mechanisms. AREAS COVERED In this article, the authors briefly review genetic models of schizophrenia, focusing on examples of how new therapeutic strategies have been developed from them. They report on the evidence of epigenetic alterations in schizophrenia and their relevance to pharmacological studies. Further, they describe the implications of epigenetic mechanisms in the etiopathogenesis of the disease and the effects of current antipsychotic drugs on epigenetic processes. Finally, they provide their perspective of using epigenetic drugs for treating schizophrenia. EXPERT OPINION Current genetic and epigenetic studies are finally shedding light on the biomolecular mechanisms linked to the core pathogenetic alterations in schizophrenia, rather than just their symptoms. These advancements in the understanding of the physiopathology of schizophrenia provide exciting new perspectives for treatments. Indeed, the possibility of looking directly at the biomolecular level allows us to bypass the age-old issues of animal studies pertaining to their questionable validity as behavioral models.
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Affiliation(s)
- Marta Bosia
- IRCCS San Raffaele Scientific Institute, Department of Clinical Neurosciences , Via Stamira d'Ancona 20, 20127 Milano , Italy +390 226 433 218 ; +390 226 433 265 ;
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Numata S, Ye T, Herman M, Lipska BK. DNA methylation changes in the postmortem dorsolateral prefrontal cortex of patients with schizophrenia. Front Genet 2014; 5:280. [PMID: 25206360 PMCID: PMC4144343 DOI: 10.3389/fgene.2014.00280] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/31/2014] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Schizophrenia is a complex psychiatric disorder with a lifetime morbidity rate of 0.5-1.0%. The pathophysiology of schizophrenia still remains obscure. Accumulating evidence indicates that DNA methylation, which is the addition of a methyl group to the cytosine in a CpG dinucleotide, might play an important role in the pathogenesis of schizophrenia. METHODS To gain further insight into the molecular mechanisms underlying schizophrenia, a genome-wide DNA methylation profiling (27,578 CpG dinucleotides spanning 14,495 genes) of the human dorsolateral prefrontal cortex (DLPFC) was conducted in a large cohort (n = 216) of well characterized specimens from individuals with schizophrenia and non-psychiatric controls, combined with an analysis of genetic variance at ~880,000 SNPs. RESULTS Aberrant DNA methylation in schizophrenia was identified at 107 CpG sites at 5% Bonferroni correction (p < 1.99 × 10(-6)). Of these significantly altered sites, hyper-DNA methylation was observed at 79 sites (73.8%), mostly in the CpG islands (CGIs) and in the regions flanking CGIs (CGI: 31 sites; CGI shore: 35 sites; CGI shelf: 3 sites). Furthermore, a large number of cis-methylation quantitative trait loci (mQTL) were identified, including associations with risk SNPs implicated in schizophrenia. CONCLUSIONS These results suggest that altered DNA methylation might be involved in the pathophysiology and/or treatment of schizophrenia, and that a combination of epigenetic and genetic approaches will be useful to understanding the molecular mechanism of this complex disorder.
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Affiliation(s)
- Shusuke Numata
- Human Brain Collection Core, National Institute of Mental Health, National Institutes of Health Bethesda, MD, USA ; Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Tokushima, Japan
| | - Tianzhang Ye
- The Lieber Institute for Brain Development, Johns Hopkins University Medical Center Baltimore, MD, USA
| | - Mary Herman
- Human Brain Collection Core, National Institute of Mental Health, National Institutes of Health Bethesda, MD, USA
| | - Barbara K Lipska
- Human Brain Collection Core, National Institute of Mental Health, National Institutes of Health Bethesda, MD, USA
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Villar-Menéndez I, Díaz-Sánchez S, Blanch M, Albasanz JL, Pereira-Veiga T, Monje A, Planchat LM, Ferrer I, Martín M, Barrachina M. Reduced striatal adenosine A2A receptor levels define a molecular subgroup in schizophrenia. J Psychiatr Res 2014; 51:49-59. [PMID: 24433848 DOI: 10.1016/j.jpsychires.2013.12.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/13/2013] [Accepted: 12/20/2013] [Indexed: 01/02/2023]
Abstract
Schizophrenia (SZ) is a mental disorder of unknown origin. Some scientific evidence seems to indicate that SZ is not a single disease entity, since there are patient groups with clear symptomatic, course and biomarker differences. SZ is characterized by a hyperdopaminergic state related to high dopamine D2 receptor activity. It has also been proposed that there is a hypoadenosynergic state. Adenosine is a nucleoside widely distributed in the organism with neuromodulative and neuroprotective activity in the central nervous system. In the brain, the most abundant adenosine receptors are A1R and A2AR. In the present report, we characterize the presence of both receptors in human postmortem putamens of patients suffering SZ with real time TaqMan PCR, western blotting and radioligand binding assay. We show that A1R levels remain unchanged with respect to age-matched controls, whereas nearly fifty percent of patients have reduced A2AR, at the transcriptional and translational levels. Moreover, we describe how DNA methylation plays a role in the pathological A2AR levels with the bisulfite-sequencing technique. In fact, an increase in 5-methylcytosine percentage in the 5' UTR region of ADORA2A was found in those SZ patients with reduced A2AR levels. Interestingly, there was a relationship between the A2A/β-actin ratio and motor disturbances as assessed with some items of the PANSS, AIMS and SAS scales. Therefore, there may be a subgroup of SZ patients with reduced striatal A2AR levels accompanied by an altered motor phenotype.
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Affiliation(s)
- Izaskun Villar-Menéndez
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - Sara Díaz-Sánchez
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Marta Blanch
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - José Luis Albasanz
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Thais Pereira-Veiga
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain
| | - Alfonso Monje
- Banc de Teixits Neurològics-Parc Sanitari Sant Joan de Déu, CIBERSAM, Sant Boi de Llobregat, Spain
| | - Luis Maria Planchat
- Banc de Teixits Neurològics-Parc Sanitari Sant Joan de Déu, CIBERSAM, Sant Boi de Llobregat, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain; Departament de Patologia i Terapèutica Experimental, Universitat de Barcelona, L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, CIBERNED, Spain
| | - Mairena Martín
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencia y Tecnologías Químicas, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, Ciudad Real, Spain; Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Medicina de Ciudad Real, CRIB, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Marta Barrachina
- Institute of Neuropathology, Bellvitge University Hospital-ICS, [Bellvitge Biomedical Research Institute-] IDIBELL, L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, CIBERNED, Spain.
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Aberg KA, McClay JL, Nerella S, Clark S, Kumar G, Chen W, Khachane AN, Xie L, Hudson A, Gao G, Harada A, Hultman CM, Sullivan PF, Magnusson PKE, van den Oord EJCG. Methylome-wide association study of schizophrenia: identifying blood biomarker signatures of environmental insults. JAMA Psychiatry 2014; 71:255-64. [PMID: 24402055 PMCID: PMC4331014 DOI: 10.1001/jamapsychiatry.2013.3730] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
IMPORTANCE Epigenetic studies present unique opportunities to advance schizophrenia research because they can potentially account for many of its clinical features and suggest novel strategies to improve disease management. OBJECTIVE To identify schizophrenia DNA methylation biomarkers in blood. DESIGN, SETTING, AND PARTICIPANTS The sample consisted of 759 schizophrenia cases and 738 controls (N = 1497) collected in Sweden. We used methyl-CpG-binding domain protein-enriched genome sequencing of the methylated genomic fraction, followed by next-generation DNA sequencing. We obtained a mean (SD) number of 68 (26.8) million reads per sample. This massive data set was processed using a specifically designed data analysis pipeline. Critical top findings from our methylome-wide association study (MWAS) were replicated in independent case-control participants using targeted pyrosequencing of bisulfite-converted DNA. MAIN OUTCOMES AND MEASURES Status of schizophrenia cases and controls. RESULTS Our MWAS suggested a considerable number of effects, with 25 sites passing the highly conservative Bonferroni correction and 139 sites significant at a false discovery rate of 0.01. Our top MWAS finding, which was located in FAM63B, replicated with P = 2.3 × 10-10. It was part of the networks regulated by microRNA that can be linked to neuronal differentiation and dopaminergic gene expression. Many other top MWAS results could be linked to hypoxia and, to a lesser extent, infection, suggesting that a record of pathogenic events may be preserved in the methylome. Our findings also implicated a site in RELN, one of the most frequently studied candidates in methylation studies of schizophrenia. CONCLUSIONS AND RELEVANCE To our knowledge, the present study is one of the first MWASs of disease with a large sample size using a technology that provides good coverage of methylation sites across the genome. Our results demonstrated one of the unique features of methylation studies that can capture signatures of environmental insults in peripheral tissues. Our MWAS suggested testable hypotheses about disease mechanisms and yielded biomarkers that can potentially be used to improve disease management.
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Affiliation(s)
- Karolina A. Aberg
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Joseph L. McClay
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Srilaxmi Nerella
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Shaunna Clark
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Gaurav Kumar
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Wenan Chen
- Department of Biostatistics, Virginia Commonwealth University, Richmond
| | - Amit N. Khachane
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Linying Xie
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Alexandra Hudson
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Guimin Gao
- Department of Biostatistics, Virginia Commonwealth University, Richmond
| | - Aki Harada
- Center for Biomarker Research and Personalized Medicine, Virginia Commonwealth University, Richmond
| | - Christina M. Hultman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Patrick F. Sullivan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden4Departments of Genetics and Psychiatry, University of North Carolina at Chapel Hill
| | - Patrik K. E. Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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Dalton VS, Kolshus E, McLoughlin DM. Epigenetics and depression: return of the repressed. J Affect Disord 2014; 155:1-12. [PMID: 24238955 DOI: 10.1016/j.jad.2013.10.028] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/15/2013] [Accepted: 10/16/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Epigenetics has recently emerged as a potential mechanism by which adverse environmental stimuli can result in persistent changes in gene expression. Epigenetic mechanisms function alongside the DNA sequence to modulate gene expression and ultimately influence protein production. The current review provides an introduction and overview of epigenetics with a particular focus on preclinical and clinical studies relevant to major depressive disorder (MDD). METHODS PubMed and Web of Science databases were interrogated from January 1995 up to December 2012 using combinations of search terms, including "epigenetic", "microRNA" and "DNA methylation" cross referenced with "depression", "early life stress" and "antidepressant". RESULTS There is an association between adverse environmental stimuli, such as early life stress, and epigenetic modification of gene expression. Epigenetic changes have been reported in humans with MDD and may serve as biomarkers to improve diagnosis. Antidepressant treatments appear to reverse or initiate compensatory epigenetic alterations that may be relevant to their mechanism of action. LIMITATIONS As a narrative review, the current report was interpretive and qualitative in nature. CONCLUSION Epigenetic modification of gene expression provides a mechanism for understanding the link between long-term effects of adverse life events and the changes in gene expression that are associated with depression. Although still a developing field, in the future, epigenetic modifications of gene expression may provide novel biomarkers to predict future susceptibility and/or onset of MDD, improve diagnosis, and aid in the development of epigenetics-based therapies for depression.
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Affiliation(s)
- Victoria S Dalton
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland; Department of Psychiatry, Trinity College Dublin, St. Patrick's University Hospital, James's Street, Dublin 8, Ireland
| | - Erik Kolshus
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland; Department of Psychiatry, Trinity College Dublin, St. Patrick's University Hospital, James's Street, Dublin 8, Ireland
| | - Declan M McLoughlin
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland; Department of Psychiatry, Trinity College Dublin, St. Patrick's University Hospital, James's Street, Dublin 8, Ireland.
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Gavin DP, Floreani C. Epigenetics of schizophrenia: an open and shut case. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 115:155-201. [PMID: 25131545 DOI: 10.1016/b978-0-12-801311-3.00005-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During the last decade and a half, there has been an explosion of data regarding epigenetic changes in schizophrenia. Most initial studies have suggested that schizophrenia is characterized by an overly restrictive chromatin state based on increases in transcription silencing histone modifications and DNA methylation at schizophrenia candidate gene promoters and increases in the expression of enzymes that catalyze their formation. However, recent studies indicate that the pathology is more complex. This complexity may greatly impact pharmacological approaches directed at targeting epigenetic abnormalities in schizophrenia. The current review explores epigenetic studies of schizophrenia and what this can tell us about the underlying pathophysiology. We hypothesize based on recent studies that it is also plausible that drugs that further restrict chromatin may be efficacious.
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Affiliation(s)
- David P Gavin
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA.
| | - Christina Floreani
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
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Guidotti A, Dong E, Tueting P, Grayson DR. Modeling the molecular epigenetic profile of psychosis in prenatally stressed mice. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 128:89-101. [PMID: 25410542 PMCID: PMC4283473 DOI: 10.1016/b978-0-12-800977-2.00004-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Based on postmortem brain studies, our overarching epigenetic hypothesis is that chronic schizophrenia (SZ) is a psychopathological condition involving dysregulation of the dynamic equilibrium among DNA methylation/demethylation network components and the expression of SZ target genes, including GABAergic and glutamatergic genes. SZ has a natural course, starting with a prodromal phase, a first episode that occurs in adolescents or in young adults, and later deterioration over the adult years. Hence, the epigenetic status at each neurodevelopmental stage of the disease cannot be studied just in postmortem brain of chronic SZ patients, but requires the use of neurodevelopmental animal models. We have directed the focus of our research toward studying the epigenetic signature of the SZ brain in the offspring of dams stressed during pregnancy (PRS mice). Adult PRS mice have behavioral deficits reminiscent of behaviors observed in psychotic patients. The adult PRS brain, like that of postmortem chronic SZ patients, is characterized by a significant increase in DNA methyltransferase 1, Tet methylcytosine dioxygenase 1 (TET1), 5-methylcytosine, and 5-hydroxymethylcytosine at SZ candidate gene promoters and a reduction in the expression of glutamatergic and GABAergic genes. In PRS mice, measurements of epigenetic biomarkers for SZ can be assessed at different stages of development with the goal of further elucidating the pathophysiology of this disease and predicting treatment responses at specific stages of the illness, with particular attention to early detection and possibly early intervention.
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Affiliation(s)
- Alessandro Guidotti
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Erbo Dong
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Patricia Tueting
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Dennis R Grayson
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
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Mitchell A, Roussos P, Peter C, Tsankova N, Akbarian S. The future of neuroepigenetics in the human brain. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 128:199-228. [PMID: 25410546 DOI: 10.1016/b978-0-12-800977-2.00008-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Complex mechanisms shape the genome of brain cells into transcriptional units, clusters of condensed chromatin, and many other features that distinguish between various cell types and developmental stages sharing the same genetic material. Only a few years ago, the field's focus was almost entirely on a single mark, CpG methylation; the emerging complexity of neuronal and glial epigenomes now includes multiple types of DNA cytosine methylation, more than 100 residue-specific posttranslational histone modifications and histone variants, all of which superimposed by a dynamic and highly regulated three-dimensional organization of the chromosomal material inside the cell nucleus. Here, we provide an update on the most innovative approaches in neuroepigenetics and their potential contributions to approach cognitive functions and disorders unique to human. We propose that comprehensive, cell type-specific mappings of DNA and histone modifications, chromatin-associated RNAs, and chromosomal "loopings" and other determinants of three-dimensional genome organization will critically advance insight into the pathophysiology of the disease. For example, superimposing the epigenetic landscapes of neuronal and glial genomes onto genetic maps for complex disorders, ranging from Alzheimer's disease to schizophrenia, could provide important clues about neurological function for some of the risk-associated noncoding sequences in the human genome.
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Affiliation(s)
- Amanda Mitchell
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Cyril Peter
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Nadejda Tsankova
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA
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Gavin DP, Chase KA, Sharma RP. Active DNA demethylation in post-mitotic neurons: a reason for optimism. Neuropharmacology 2013; 75:233-45. [PMID: 23958448 DOI: 10.1016/j.neuropharm.2013.07.036] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 07/22/2013] [Accepted: 07/30/2013] [Indexed: 12/13/2022]
Abstract
Over the last several years proteins involved in base excision repair (BER) have been implicated in active DNA demethylation. We review the literature supporting BER as a means of active DNA demethylation, and explain how the various components function and cooperate to remove the potentially most enduring means of epigenetic gene regulation. Recent evidence indicates that the same pathways implicated during periods of widespread DNA demethylation, such as the erasure of methyl marks in the paternal pronucleus soon after fertilization, are operational in post-mitotic neurons. Neuronal functional identities, defined here as the result of a combination of neuronal subtype, location, and synaptic connections are largely maintained through DNA methylation. Chronic mental illnesses, such as schizophrenia, may be the result of both altered neurotransmitter levels and neurons that have assumed dysfunctional neuronal identities. A limitation of most current psychopharmacological agents is their focus on the former, while not addressing the more profound latter pathophysiological process. Previously, it was believed that active DNA demethylation in post-mitotic neurons was rare if not impossible. If this were the case, then reversing the factors that maintain neuronal identity, would be highly unlikely. The emergence of an active DNA demethylation pathway in the brain is a reason for great optimism in psychiatry as it provides a means by which previously pathological neurons may be reprogrammed to serve a more favorable role. Agents targeting epigenetic processes have shown much promise in this regard, and may lead to substantial gains over traditional pharmacological approaches.
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Affiliation(s)
- David P Gavin
- The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA; Jesse Brown Veterans Affairs Medical Center, 820 South Damen Avenue (M/C 151), Chicago, IL 60612, USA.
| | - Kayla A Chase
- The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA
| | - Rajiv P Sharma
- The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA; Jesse Brown Veterans Affairs Medical Center, 820 South Damen Avenue (M/C 151), Chicago, IL 60612, USA
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Lahiri DK, Maloney B. Gene × environment interaction by a longitudinal epigenome-wide association study (LEWAS) overcomes limitations of genome-wide association study (GWAS). Epigenomics 2013; 4:685-99. [PMID: 23244313 DOI: 10.2217/epi.12.60] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The goal of genome-wide association studies is to identify SNPs unique to disease. It usually involves a single sampling from subjects' lifetimes. While primary DNA sequence variation influences gene-expression levels, expression is also influenced by epigenetics, including the 'somatic epitype' (G(SE)), an epigenotype acquired postnatally. While genes are inherited, and novel polymorphisms do not routinely appear, G(SE) is fluid. Furthermore, G(SE) could respond to environmental factors (such as heavy metals) and to differences in exercise, maternal care and dietary supplements - all of which postnatally modify oxidation or methylation of DNA, leading to altered gene expression. Change in epigenetic status may be critical for the development of many diseases. We propose a 'longitudinal epigenome-wide association study', wherein G(SE) are measured at multiple time points along with subjects' histories. This Longitudinal epigenome-wide association study, based on the 'dynamic' somatic epitype over the 'static' genotype, merits further investigation.
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Affiliation(s)
- Debomoy K Lahiri
- Department of Psychiatry, Laboratory of Molecular Neurogenetics, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Ozomaro U, Wahlestedt C, Nemeroff CB. Personalized medicine in psychiatry: problems and promises. BMC Med 2013; 11:132. [PMID: 23680237 PMCID: PMC3668172 DOI: 10.1186/1741-7015-11-132] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 04/19/2013] [Indexed: 01/29/2023] Open
Abstract
The central theme of personalized medicine is the premise that an individual's unique physiologic characteristics play a significant role in both disease vulnerability and in response to specific therapies. The major goals of personalized medicine are therefore to predict an individual's susceptibility to developing an illness, achieve accurate diagnosis, and optimize the most efficient and favorable response to treatment. The goal of achieving personalized medicine in psychiatry is a laudable one, because its attainment should be associated with a marked reduction in morbidity and mortality. In this review, we summarize an illustrative selection of studies that are laying the foundation towards personalizing medicine in major depressive disorder, bipolar disorder, and schizophrenia. In addition, we present emerging applications that are likely to advance personalized medicine in psychiatry, with an emphasis on novel biomarkers and neuroimaging.
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Affiliation(s)
- Uzoezi Ozomaro
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Claes Wahlestedt
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
- Center for Therapeutic Innovation, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Charles B Nemeroff
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
- Center for Therapeutic Innovation, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
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Nishioka M, Shimada T, Bundo M, Ukai W, Hashimoto E, Saito T, Kano Y, Sasaki T, Kasai K, Kato T, Iwamoto K. WITHDRAWN: Neuronal cell-type specific DNA methylation patterns of the Cacna1cgene. Int J Dev Neurosci 2013:S0736-5748(13)00067-1. [PMID: 23669180 DOI: 10.1016/j.ijdevneu.2013.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/02/2012] [Accepted: 11/16/2012] [Indexed: 11/18/2022] Open
Abstract
The Publisher regrets that this article is an accidental duplication of an articlethat has already been published, http://dx.doi.org/10.1016/j.ijdevneu.2012.11.007. The duplicate article has therefore been withdrawn.
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Affiliation(s)
- Masaki Nishioka
- Department of Molecular Psychiatry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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Folsom TD, Fatemi SH. The involvement of Reelin in neurodevelopmental disorders. Neuropharmacology 2013; 68:122-35. [PMID: 22981949 PMCID: PMC3632377 DOI: 10.1016/j.neuropharm.2012.08.015] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 08/14/2012] [Accepted: 08/16/2012] [Indexed: 12/21/2022]
Abstract
Reelin is a glycoprotein that serves important roles both during development (regulation of neuronal migration and brain lamination) and in adulthood (maintenance of synaptic function). A number of neuropsychiatric disorders including autism, schizophrenia, bipolar disorder, major depression, Alzheimer's disease and lissencephaly share a common feature of abnormal Reelin expression in the brain. Altered Reelin expression has been hypothesized to impair neuronal connectivity and synaptic plasticity, leading ultimately to the cognitive deficits present in these disorders. The mechanisms for abnormal Reelin expression in some of these disorders are currently unknown although possible explanations include early developmental insults, mutations, hypermethylation of the promoter for the Reelin gene (RELN), miRNA silencing of Reelin mRNA, FMRP underexpression and Reelin processing abnormalities. Increasing Reelin expression through pharmacological therapies may help ameliorate symptoms resulting from Reelin deficits. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.
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Affiliation(s)
- Timothy D. Folsom
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, 420 Delaware St SE, MMC 392, Minneapolis, MN 55455, USA
| | - S. Hossein Fatemi
- Department of Psychiatry, Division of Neuroscience Research, University of Minnesota Medical School, 420 Delaware St SE, MMC 392, Minneapolis, MN 55455, USA
- Department of Pharmacology, University of Minnesota Medical School, 420 Delaware St SE, MMC 392, Minneapolis, MN 55455, USA
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware St SE, MMC 392, Minneapolis, MN 55455, USA
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