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McGregor K, Labbe A, Greenwood CMT. Response to: Correcting for cell-type effects in DNA methylation studies: reference-based method outperforms latent variable approaches in empirical studies. Genome Biol 2017; 18:25. [PMID: 28137287 PMCID: PMC5282700 DOI: 10.1186/s13059-017-1149-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We thank Hattab and colleagues for their correspondence and their investigation of cell-type mixture correction methods in methyl-CG binding domain sequencing. Here, we speculate on why surrogate variable analysis (SVA) performed differently between their two data sets, and poorly in one of them. Please see related Correspondence article: https://genomebiology.biomedcentral.com/articles/10/1186/s13059-017-1148-8 and related Research article: https://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-0935-y
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Affiliation(s)
- Kevin McGregor
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
| | - Aurélie Labbe
- Department of Decision Sciences, HEC Montreal, Montreal, QC, Canada
| | - Celia M T Greenwood
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada. .,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada. .,Departments of Oncology and Human Genetics, McGill University, Montreal, QC, Canada.
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102
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Hattab MW, Shabalin AA, Clark SL, Zhao M, Kumar G, Chan RF, Xie LY, Jansen R, Han LKM, Magnusson PKE, van Grootheest G, Hultman CM, Penninx BWJH, Aberg KA, van den Oord EJCG. Correcting for cell-type effects in DNA methylation studies: reference-based method outperforms latent variable approaches in empirical studies. Genome Biol 2017; 18:24. [PMID: 28137292 PMCID: PMC5282865 DOI: 10.1186/s13059-017-1148-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Based on an extensive simulation study, McGregor and colleagues recently recommended the use of surrogate variable analysis (SVA) to control for the confounding effects of cell-type heterogeneity in DNA methylation association studies in scenarios where no cell-type proportions are available. As their recommendation was mainly based on simulated data, we sought to replicate findings in two large-scale empirical studies. In our empirical data, SVA did not fully correct for cell-type effects, its performance was somewhat unstable, and it carried a risk of missing true signals caused by removing variation that might be linked to actual disease processes. By contrast, a reference-based correction method performed well and did not show these limitations. A disadvantage of this approach is that if reference methylomes are not (publicly) available, they will need to be generated once for a small set of samples. However, given the notable risk we observed for cell-type confounding, we argue that, to avoid introducing false-positive findings into the literature, it could be well worth making this investment.Please see related Correspondence article: https://genomebiology.biomedcentral.com/articles/10/1186/s13059-017-1149-7 and related Research article: https://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-0935-y.
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Affiliation(s)
- Mohammad W Hattab
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Andrey A Shabalin
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Shaunna L Clark
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Min Zhao
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Gaurav Kumar
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Robin F Chan
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Lin Ying Xie
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Rick Jansen
- Department of Psychiatry, VU University Medical Center/GGZ inGeest, Amsterdam, The Netherlands
| | - Laura K M Han
- Department of Psychiatry, VU University Medical Center/GGZ inGeest, Amsterdam, The Netherlands
| | - Patrik K E Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Gerard van Grootheest
- Department of Psychiatry, VU University Medical Center/GGZ inGeest, Amsterdam, The Netherlands
| | - Christina M Hultman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Brenda W J H Penninx
- Department of Psychiatry, VU University Medical Center/GGZ inGeest, Amsterdam, The Netherlands
| | - Karolina A Aberg
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Edwin J C G van den Oord
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA.
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103
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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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104
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Abstract
First, we describe the hallmark contributions of Irv Gottesman's pioneering scholarship for schizophrenia research including concepts of polygenicity, gene × environment interactions, epigenetics and the endophenotype concept. Gottesman and colleagues' twin studies showed that genes, not social factors, mediate schizophrenia risk. He then showed that schizophrenia is highly polygenic. Next, he introduced the concept of epigenetics into schizophrenia research. Gottesman then introduced the quantitative endophenotype concept. Endophenotypes are laboratory-based measures that show deficits in schizophrenia patients and lesser deficits in their first degree "unaffected" relatives and are viewed as being more proximal to genes and having a simpler genetic architecture than are "fuzzy" qualitative diagnostic disorders. Endophenotypes offer an exciting path to gene discovery, neural circuits, genetic architecture and new treatment pathways of schizophrenia and related psychotic disorders. Second, we were asked to discuss 2 of many endophenotype Consortia and related studies, in order to illustrate the impact of Gottesman's work. We describe the Consortium on the Genetics of Schizophrenia (COGS) exploring neurocognitive and neurophysiological endophenotypes in family and case-control studies. Association, linkage, sequencing and epigenetic studies are described. The Bipolar and Schizophrenia Network for Intermediate Phenotypes (BSNIP) uses an array of endophenotypes including brain imaging in studies across the psychosis dimension, allowing for dimensional analyses. BSNIP results have led to the concept of biotypes, advancing the field. Irv Gottesman was imaginatively prescient in generating novel insights and predicting many major issues which challenge schizophrenia researchers who still use his concepts to guide current research approaches.
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Affiliation(s)
- David L Braff
- Department of Psychiatry, University of California, San Diego, La Jolla, CA;
| | - Carol A Tamminga
- Department of Psychiatry, UT Southwestern Medical School, Dallas, TX
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105
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Li H, Zhang Q, Li N, Wang F, Xiang H, Zhang Z, Su Y, Huang Y, Zhang S, Zhao G, Zhou R, Mao L, Lin Z, Cai W, Fang Y, Xie B, Zhao M, Hong W. Plasma levels of Th17-related cytokines and complement C3 correlated with aggressive behavior in patients with schizophrenia. Psychiatry Res 2016; 246:700-706. [PMID: 27829509 DOI: 10.1016/j.psychres.2016.10.061] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 10/13/2016] [Accepted: 10/20/2016] [Indexed: 12/18/2022]
Abstract
Increasing evidence indicates that immune inflammatory processes, especially autoimmune reaction, should be considered in the pathophysiology of schizophrenia and aggressive behavior. The present study aimed to explore the correlation between immune factors (C3 and Th17-related cytokines) and aggressive behavior in schizophrenia patients. Forty schizophrenia patients and forty age- and gender-matched healthy controls participated in the study. Blood samples were assessed by ELISA upon enrollment. Positive and negative syndrome scale (PANSS) and modified overt aggression scale (MOAS) were used to estimate the severity and aggressive symptoms of schizophrenia patients. Plasma levels of IL-17, IL-23, and TGF-β1 in schizophrenia patients were significantly higher than those in healthy controls [(37.63±17.82) vs. (29.34±10.38)pg/ml, p=0.02; (101.40±135.26) vs. (13.09±5.94) pg/ml, p=0.01; (2864.57±2163.61) vs. (1839.69±1797.73)pg/ml, p=0.04], whereas C3 levels were significantly lower in schizophrenia patients [( 120,479.67± 65,612.50) vs. ( 208,060.21± 217,008.21)ng/ml, p=0.02]. IL-17, IL-23, and TGF-β1 levels were positively related to total scores of MOAS (p=0.02, p=0.02 and p=0.03, respectively) and PANSS (p=0.04, p=0.04 and p=0.02, respectively), whereas C3 levels were negatively related to total PANSS scores (p=0.03). IL-17 and IL-23 levels were positively correlated with PANSS excited component scores (p=0.04 and p=0.01, respectively). Our findings suggested that the Th17-related cytokine levels were positively related to the severity of schizophrenia and aggressive behavior, whereas C3 levels were negatively related to the severity of schizophrenia. This study demonstrated that elevated levels of Th17-related cytokines and decreased levels of C3 could be potential biomarkers for schizophrenia and aggressive behavior.
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Affiliation(s)
- Haozhe Li
- Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Service Platform, Institute of Forensic Science, Ministry of Justice, PR China, Shanghai, China; Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qinting Zhang
- Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Service Platform, Institute of Forensic Science, Ministry of Justice, PR China, Shanghai, China; Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Ningning Li
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fan Wang
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui Xiang
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zongfeng Zhang
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yousong Su
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yueqi Huang
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shengyu Zhang
- Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Service Platform, Institute of Forensic Science, Ministry of Justice, PR China, Shanghai, China
| | - Guoqing Zhao
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Rubai Zhou
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ling Mao
- XuHui District Mental Health Center of Shanghai, Shanghai, China
| | - Zhiguang Lin
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weixiong Cai
- Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Service Platform, Institute of Forensic Science, Ministry of Justice, PR China, Shanghai, China
| | - Yiru Fang
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Xie
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Zhao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wu Hong
- Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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106
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Insights into psychosis risk from leukocyte microRNA expression. Transl Psychiatry 2016; 6:e981. [PMID: 27959328 PMCID: PMC5290334 DOI: 10.1038/tp.2016.148] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 06/17/2016] [Accepted: 06/30/2016] [Indexed: 11/11/2022] Open
Abstract
Dysregulation of immune system functions has been implicated in schizophrenia, suggesting that immune cells may be involved in the development of the disorder. With the goal of a biomarker assay for psychosis risk, we performed small RNA sequencing on RNA isolated from circulating immune cells. We compared baseline microRNA (miRNA) expression for persons who were unaffected (n=27) or who, over a subsequent 2-year period, were at clinical high risk but did not progress to psychosis (n=37), or were at high risk and did progress to psychosis (n=30). A greedy algorithm process led to selection of five miRNAs that when summed with +1 weights distinguished progressed from nonprogressed subjects with an area under the receiver operating characteristic curve of 0.86. Of the five, miR-941 is human-specific with incompletely understood functions, but the other four are prominent in multiple immune system pathways. Three of those four are downregulated in progressed vs. nonprogressed subjects (with weight -1 in a classifier function that increases with risk); all three have also been independently reported as downregulated in monocytes from schizophrenia patients vs. unaffected subjects. Importantly, these findings passed stringent randomization tests that minimized the risk of conclusions arising by chance. Regarding miRNA-miRNA correlations over the three groups, progressed subjects were found to have much weaker miRNA orchestration than nonprogressed or unaffected subjects. If independently verified, the leukocytic miRNA biomarker assay might improve accuracy of psychosis high-risk assessments and eventually help rationalize preventative intervention decisions.
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107
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Huang JH, Park H, Iaconelli J, Berkovitch SS, Watmuff B, McPhie D, Öngür D, Cohen BM, Clish CB, Karmacharya R. Unbiased Metabolite Profiling of Schizophrenia Fibroblasts under Stressful Perturbations Reveals Dysregulation of Plasmalogens and Phosphatidylcholines. J Proteome Res 2016; 16:481-493. [DOI: 10.1021/acs.jproteome.6b00628] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Joanne H. Huang
- Center
for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental
Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
| | - Hyoungjun Park
- Institute
of Neuroinformatics, ETH Zurich and University of Zurich, CH-8057, Zurich, Switzerland
| | - Jonathan Iaconelli
- Center
for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental
Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
| | - Shaunna S. Berkovitch
- Center
for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental
Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
| | - Bradley Watmuff
- Center
for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental
Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
| | - Donna McPhie
- Schizophrenia
and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, United States
| | - Dost Öngür
- Schizophrenia
and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, United States
| | - Bruce M. Cohen
- Schizophrenia
and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, United States
| | - Clary B. Clish
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
| | - Rakesh Karmacharya
- Center
for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental
Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Chemical
Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, United States
- Schizophrenia
and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, United States
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108
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Fisher HL, Murphy TM, Arseneault L, Caspi A, Moffitt TE, Viana J, Hannon E, Pidsley R, Burrage J, Dempster EL, Wong CCY, Pariante CM, Mill J. Methylomic analysis of monozygotic twins discordant for childhood psychotic symptoms. Epigenetics 2016; 10:1014-23. [PMID: 26479702 PMCID: PMC4867769 DOI: 10.1080/15592294.2015.1099797] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Childhood psychotic symptoms are associated with increased rates of schizophrenia, other psychiatric disorders, and suicide attempts in adulthood; thus, elucidating early risk indicators is crucial to target prevention efforts. There is considerable discordance for psychotic symptoms between monozygotic twins, indicating that child-specific non-genetic factors must be involved. Epigenetic processes may constitute one of these factors and have not yet been investigated in relation to childhood psychotic symptoms. Therefore, this study explored whether differences in DNA methylation at age 10 were associated with monozygotic twin discordance for psychotic symptoms at age 12. The Environmental Risk (E-Risk) Longitudinal Twin Study cohort of 2,232 children (1,116 twin pairs) was assessed for age-12 psychotic symptoms and 24 monozygotic twin pairs discordant for symptoms were identified for methylomic comparison. Children provided buccal samples at ages 5 and 10. DNA was bisulfite modified and DNA methylation was quantified using the Infinium HumanMethylation450 array. Differentially methylated positions (DMPs) associated with psychotic symptoms were subsequently tested in post-mortem prefrontal cortex tissue from adult schizophrenia patients and age-matched controls. Site-specific DNA methylation differences were observed at age 10 between monozygotic twins discordant for age-12 psychotic symptoms. Similar DMPs were not found at age 5. The top-ranked psychosis-associated DMP (cg23933044), located in the promoter of the C5ORF42 gene, was also hypomethylated in post-mortem prefrontal cortex brain tissue from schizophrenia patients compared to unaffected controls. These data tentatively suggest that epigenetic variation in peripheral tissue is associated with childhood psychotic symptoms and may indicate susceptibility to schizophrenia and other mental health problems.
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Affiliation(s)
- Helen L Fisher
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK
| | - Therese M Murphy
- b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
| | - Louise Arseneault
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK
| | - Avshalom Caspi
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK.,c Department of Psychology and Neuroscience ; Duke University ; Durham , NC , USA.,d Department of Psychiatry and Behavioral Sciences ; Duke University Medical School ; Durham , NC , USA
| | - Terrie E Moffitt
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK.,c Department of Psychology and Neuroscience ; Duke University ; Durham , NC , USA.,d Department of Psychiatry and Behavioral Sciences ; Duke University Medical School ; Durham , NC , USA
| | - Joana Viana
- b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
| | - Eilis Hannon
- b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
| | - Ruth Pidsley
- e Garvan Institute of Medical Research ; Darlinghurst , NSW , Australia
| | - Joe Burrage
- b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
| | - Emma L Dempster
- b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
| | - Chloe C Y Wong
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK
| | - Carmine M Pariante
- f Department of Psychological Medicine ; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK
| | - Jonathan Mill
- a MRC Social , Genetic & Developmental Psychiatry Center; Institute of Psychiatry , Psychology & Neuroscience; King's College London ; London , UK.,b University of Exeter Medical School; University of Exeter ; Exeter , Devon , UK
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109
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Abstract
Several recent studies have investigated either genetic or epigenetic variation in schizophrenia. A recent study presents comprehensive analyses of blood samples to better characterize the combined role of genetic and epigenetic variation in schizophrenia. While the paper identifies significant associations with schizophrenia risk and diagnosis, the potential relevance to the brain in schizophrenia is questionable.
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Affiliation(s)
- Andrew E Jaffe
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD, 21205, USA. .,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA. .,Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA. .,Center for Computational Biology, Johns Hopkins University, Baltimore, MD, 21205, USA.
| | - Joel E Kleinman
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD, 21205, USA.,Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
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110
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Consistently altered expression of gene sets in postmortem brains of individuals with major psychiatric disorders. Transl Psychiatry 2016; 6:e890. [PMID: 27622934 PMCID: PMC5048210 DOI: 10.1038/tp.2016.173] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/18/2016] [Indexed: 12/25/2022] Open
Abstract
The measurement of gene expression in postmortem brain is an important tool for understanding the pathogenesis of serious psychiatric disorders. We hypothesized that major molecular deficits associated with psychiatric disease would affect the entire brain, and such deficits may be shared across disorders. We performed RNA sequencing and quantified gene expression in the hippocampus of 100 brains in the Stanley Array Collection followed by replication in the orbitofrontal cortex of 57 brains in the Stanley Neuropathology Consortium. We then identified genes and canonical pathway gene sets with significantly altered expression in schizophrenia and bipolar disorder in the hippocampus and in schizophrenia, bipolar disorder and major depression in the orbitofrontal cortex. Although expression of individual genes varied, gene sets were significantly enriched in both of the brain regions, and many of these were consistent across diagnostic groups. Further examination of core gene sets with consistently increased or decreased expression in both of the brain regions and across target disorders revealed that ribosomal genes are overexpressed while genes involved in neuronal processes, GABAergic signaling, endocytosis and antigen processing have predominantly decreased expression in affected individuals compared to controls without a psychiatric disorder. Our results highlight pathways of central importance to psychiatric health and emphasize messenger RNA processing and protein synthesis as potential therapeutic targets for all three of the disorders.
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111
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Tomasik J, Rahmoune H, Guest PC, Bahn S. Neuroimmune biomarkers in schizophrenia. Schizophr Res 2016; 176:3-13. [PMID: 25124519 DOI: 10.1016/j.schres.2014.07.025] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/17/2014] [Accepted: 07/20/2014] [Indexed: 02/07/2023]
Abstract
Schizophrenia is a heterogeneous psychiatric disorder with a broad spectrum of clinical and biological manifestations. Due to the lack of objective tests, the accurate diagnosis and selection of effective treatments for schizophrenia remains challenging. Numerous technologies have been employed in search of schizophrenia biomarkers. These studies have suggested that neuroinflammatory processes may play a role in schizophrenia pathogenesis, at least in a subgroup of patients. The evidence indicates alterations in both pro- and anti-inflammatory molecules in the central nervous system, which have also been found in peripheral tissues and may correlate with schizophrenia symptoms. In line with these findings, certain immunomodulatory interventions have shown beneficial effects on psychotic symptoms in schizophrenia patients, in particular those with distinct immune signatures. In this review, we evaluate these findings and their potential for more targeted drug interventions and the development of companion diagnostics. Although currently no validated markers exist for schizophrenia patient stratification or the prediction of treatment efficacy, we propose that utilisation of inflammatory markers for diagnostic and theranostic purposes may lead to novel therapeutic approaches and deliver more effective care for schizophrenia patients.
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Affiliation(s)
- Jakub Tomasik
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK; Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Hassan Rahmoune
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Paul C Guest
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Sabine Bahn
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK; Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands.
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112
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Hannon E, Dempster E, Viana J, Burrage J, Smith AR, Macdonald R, St Clair D, Mustard C, Breen G, Therman S, Kaprio J, Toulopoulou T, Pol HEH, Bohlken MM, Kahn RS, Nenadic I, Hultman CM, Murray RM, Collier DA, Bass N, Gurling H, McQuillin A, Schalkwyk L, Mill J. An integrated genetic-epigenetic analysis of schizophrenia: evidence for co-localization of genetic associations and differential DNA methylation. Genome Biol 2016; 17:176. [PMID: 27572077 PMCID: PMC5004279 DOI: 10.1186/s13059-016-1041-x] [Citation(s) in RCA: 212] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/09/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Schizophrenia is a highly heritable, neuropsychiatric disorder characterized by episodic psychosis and altered cognitive function. Despite success in identifying genetic variants associated with schizophrenia, there remains uncertainty about the causal genes involved in disease pathogenesis and how their function is regulated. RESULTS We performed a multi-stage epigenome-wide association study, quantifying genome-wide patterns of DNA methylation in a total of 1714 individuals from three independent sample cohorts. We have identified multiple differentially methylated positions and regions consistently associated with schizophrenia across the three cohorts; these effects are independent of important confounders such as smoking. We also show that epigenetic variation at multiple loci across the genome contributes to the polygenic nature of schizophrenia. Finally, we show how DNA methylation quantitative trait loci in combination with Bayesian co-localization analyses can be used to annotate extended genomic regions nominated by studies of schizophrenia, and to identify potential regulatory variation causally involved in disease. CONCLUSIONS This study represents the first systematic integrated analysis of genetic and epigenetic variation in schizophrenia, introducing a methodological approach that can be used to inform epigenome-wide association study analyses of other complex traits and diseases. We demonstrate the utility of using a polygenic risk score to identify molecular variation associated with etiological variation, and of using DNA methylation quantitative trait loci to refine the functional and regulatory variation associated with schizophrenia risk variants. Finally, we present strong evidence for the co-localization of genetic associations for schizophrenia and differential DNA methylation.
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Affiliation(s)
- Eilis Hannon
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Emma Dempster
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Joana Viana
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Joe Burrage
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Adam R. Smith
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Ruby Macdonald
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - David St Clair
- The Institute of Medical Sciences, Aberdeen University, Aberdeen, UK
| | | | - Gerome Breen
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, London, UK
| | | | - Jaakko Kaprio
- National Institute for Health and Welfare, Helsinki, Finland
- Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Public Health, University of Helsinki, Helsinki, Finland
| | | | - Hilleke E. Hulshoff Pol
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marc M. Bohlken
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rene S. Kahn
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Igor Nenadic
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Christina M. Hultman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden
| | - Robin M. Murray
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, London, UK
| | - David A. Collier
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, London, UK
- Eli Lilly and Company Ltd, Windlesham, UK
| | - Nick Bass
- Division of Psychiatry, University College London, London, UK
| | - Hugh Gurling
- Division of Psychiatry, University College London, London, UK
| | | | - Leonard Schalkwyk
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, London, UK
- School of Biological Sciences, University of Essex, Colchester, UK
| | - Jonathan Mill
- University of Exeter Medical School, University of Exeter, Exeter, UK
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, London, UK
- Royal Devon & Exeter Hospital, RILD Building, Level 4, Barrack Rd, Exeter, EX2 5DW UK
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113
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Klein HU, De Jager PL. Uncovering the Role of the Methylome in Dementia and Neurodegeneration. Trends Mol Med 2016; 22:687-700. [PMID: 27423266 DOI: 10.1016/j.molmed.2016.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 06/13/2016] [Accepted: 06/15/2016] [Indexed: 12/14/2022]
Abstract
Our understanding of the epigenome has advanced dramatically over the past decade, particularly in terms of DNA methylation, a modification found throughout the genome. Studies of the brain and neurons have outlined an increasingly complex architecture involving not just CG dinucleotide methylation but also methylation of other dinucleotides, and modifications of methylated bases such as 5-hydroxymethylcytosine. Different modifications may play an important role in brain development, function and decline; recent descriptions of the effects of aging and neurodegenerative processes such as Alzheimer disease on methylation profiles have ushered in an era of DNA methylome-wide association studies. Rapidly improving technologies and study designs are returning robust results, and investigations of the human brain's epigenome are increasingly feasible, complementing insights gained from genetic studies.
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Affiliation(s)
- Hans-Ulrich Klein
- Program in Translational Neuropsychiatric Genomics and Partners Multiple Sclerosis Center, Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Philip L De Jager
- Program in Translational Neuropsychiatric Genomics and Partners Multiple Sclerosis Center, Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA.
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114
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van den Oord EJCG, Clark SL, Xie LY, Shabalin AA, Dozmorov MG, Kumar G, Vladimirov VI, Magnusson PKE, Aberg KA. A Whole Methylome CpG-SNP Association Study of Psychosis in Blood and Brain Tissue. Schizophr Bull 2016; 42:1018-26. [PMID: 26656881 PMCID: PMC4903046 DOI: 10.1093/schbul/sbv182] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Mutated CpG sites (CpG-SNPs) are potential hotspots for human diseases because in addition to the sequence variation they may show individual differences in DNA methylation. We performed methylome-wide association studies (MWAS) to test whether methylation differences at those sites were associated with schizophrenia. We assayed all common CpG-SNPs with methyl-CpG binding domain protein-enriched genome sequencing (MBD-seq) using DNA extracted from 1408 blood samples and 66 postmortem brain samples (BA10) of schizophrenia cases and controls. Seven CpG-SNPs passed our FDR threshold of 0.1 in the blood MWAS. Of the CpG-SNPs methylated in brain, 94% were also methylated in blood. This significantly exceeded the 46.2% overlap expected by chance (P-value < 1.0×10(-8)) and justified replicating findings from blood in brain tissue. CpG-SNP rs3796293 in IL1RAP replicated (P-value = .003) with the same direction of effects. This site was further validated through targeted bisulfite pyrosequencing in 736 independent case-control blood samples (P-value < 9.5×10(-4)). Our top result in the brain MWAS (P-value = 8.8×10(-7)) was CpG-SNP rs16872141 located in the potential promoter of ENC1. Overall, our results suggested that CpG-SNP methylation may reflect effects of environmental insults and can provide biomarkers in blood that could potentially improve disease management.
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Affiliation(s)
- Edwin J C G van den Oord
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA;
| | - Shaunna L Clark
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA
| | - Lin Ying Xie
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA
| | - Andrey A Shabalin
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA
| | - Mikhail G Dozmorov
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA
| | - Gaurav Kumar
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA
| | - Vladimir I Vladimirov
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA; Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA; Lieber Institute for Brain Development, Johns Hopkins University, Baltimore, MD
| | - Patrik K E Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Karolina A Aberg
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA
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115
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Huang JH, Berkovitch SS, Iaconelli J, Watmuff B, Park H, Chattopadhyay S, McPhie D, Öngür D, Cohen BM, Clish CB, Karmacharya R. Perturbational Profiling of Metabolites in Patient Fibroblasts Implicates α-Aminoadipate as a Potential Biomarker for Bipolar Disorder. MOLECULAR NEUROPSYCHIATRY 2016; 2:97-106. [PMID: 27606323 DOI: 10.1159/000446654] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 05/04/2016] [Indexed: 12/27/2022]
Abstract
Many studies suggest the presence of aberrations in cellular metabolism in bipolar disorder. We studied the metabolome in bipolar disorder to gain insight into cellular pathways that may be dysregulated in bipolar disorder and to discover evidence of novel biomarkers. We measured polar and nonpolar metabolites in fibroblasts from subjects with bipolar I disorder and matched healthy control subjects, under normal conditions and with two physiologic perturbations: low-glucose media and exposure to the stress-mediating hormone dexamethasone. Metabolites that were significantly different between bipolar and control subjects showed distinct separation by principal components analysis methods. The most statistically significant findings were observed in the perturbation experiments. The metabolite with the lowest p value in both the low-glucose and dexamethasone experiments was α-aminoadipate, whose intracellular level was consistently lower in bipolar subjects. Our study implicates α-aminoadipate as a possible biomarker in bipolar disorder that manifests under cellular stress. This is an intriguing finding given the known role of α-aminoadipate in the modulation of kynurenic acid in the brain, especially as abnormal kynurenic acid levels have been implicated in bipolar disorder.
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Affiliation(s)
- Joanne H Huang
- Center for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Shaunna S Berkovitch
- Center for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Jonathan Iaconelli
- Center for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Bradley Watmuff
- Center for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Hyoungjun Park
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Mass., USA
| | - Shrikanta Chattopadhyay
- MGH Cancer Center, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Donna McPhie
- Schizophrenia and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Mass., USA
| | - Dost Öngür
- Schizophrenia and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Mass., USA
| | - Bruce M Cohen
- Schizophrenia and Bipolar Disorder Program, Harvard Medical School and McLean Hospital, Belmont, Mass., USA
| | - Clary B Clish
- Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
| | - Rakesh Karmacharya
- Center for Experimental Drugs and Diagnostics, Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School and Massachusetts General Hospital, Boston, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA; Chemical Biology Program, Broad Institute of Harvard and MIT, Mass., USA
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116
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Yao B, Christian KM, He C, Jin P, Ming GL, Song H. Epigenetic mechanisms in neurogenesis. Nat Rev Neurosci 2016; 17:537-49. [PMID: 27334043 DOI: 10.1038/nrn.2016.70] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the embryonic and adult brain, neural stem cells proliferate and give rise to neurons and glia through highly regulated processes. Epigenetic mechanisms - including DNA and histone modifications, as well as regulation by non-coding RNAs - have pivotal roles in different stages of neurogenesis. Aberrant epigenetic regulation also contributes to the pathogenesis of various brain disorders. Here, we review recent advances in our understanding of epigenetic regulation in neurogenesis and its dysregulation in brain disorders, including discussion of newly identified DNA cytosine modifications. We also briefly cover the emerging field of epitranscriptomics, which involves modifications of mRNAs and long non-coding RNAs.
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Affiliation(s)
- Bing Yao
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Kimberly M Christian
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Chuan He
- Department of Chemistry, Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.,Howard Hughes Medical Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, Georgia 30322, USA
| | - Guo-Li Ming
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, Maryland 21205, USA
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117
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Fries GR, Li Q, McAlpin B, Rein T, Walss-Bass C, Soares JC, Quevedo J. The role of DNA methylation in the pathophysiology and treatment of bipolar disorder. Neurosci Biobehav Rev 2016; 68:474-488. [PMID: 27328785 DOI: 10.1016/j.neubiorev.2016.06.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 06/03/2016] [Accepted: 06/12/2016] [Indexed: 12/31/2022]
Abstract
Bipolar disorder (BD) is a multifactorial illness thought to result from an interaction between genetic susceptibility and environmental stimuli. Epigenetic mechanisms, including DNA methylation, can modulate gene expression in response to the environment, and therefore might account for part of the heritability reported for BD. This paper aims to review evidence of the potential role of DNA methylation in the pathophysiology and treatment of BD. In summary, several studies suggest that alterations in DNA methylation may play an important role in the dysregulation of gene expression in BD, and some actually suggest their potential use as biomarkers to improve diagnosis, prognosis, and assessment of response to treatment. This is also supported by reports of alterations in the levels of DNA methyltransferases in patients and in the mechanism of action of classical mood stabilizers. In this sense, targeting specific alterations in DNA methylation represents exciting new treatment possibilities for BD, and the 'plastic' characteristic of DNA methylation accounts for a promising possibility of restoring environment-induced modifications in patients.
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Affiliation(s)
- Gabriel R Fries
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), 1941 East Rd, 77054, Houston, TX, USA.
| | - Qiongzhen Li
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), 1941 East Rd, 77054, Houston, TX, USA
| | - Blake McAlpin
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), 1941 East Rd, 77054, Houston, TX, USA
| | - Theo Rein
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Kraepelinstraße 2-10, 80804, Munich, Germany
| | - Consuelo Walss-Bass
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), 1941 East Rd, 77054, Houston, TX, USA; Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| | - Jair C Soares
- Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Joao Quevedo
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), 1941 East Rd, 77054, Houston, TX, USA; Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA; Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA; Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
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118
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Li F, Karlsson H. Expression and regulation of human endogenous retrovirus W elements. APMIS 2016; 124:52-66. [PMID: 26818262 DOI: 10.1111/apm.12478] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 10/12/2015] [Indexed: 01/06/2023]
Abstract
Human endogenous retroviruses (HERV) comprise 8% of the human genome and can be classified into at least 31 families. A typical HERV provirus consists of internal gag, pol and env genes, flanked by two long terminal repeats (LTRs). No single provirus is capable of engendering infectious particles. HERV are by nature repetitive and have with few notable exceptions lost their protein-coding capacity. Therefore, HERV have consistently been excluded from array-based expression studies and hence little is known of their expression, regulation, and potential functional significance. An increasing number of studies have, however, observed expression of the W family of HERV in various human tissues and cells, predominantly in placenta. HERV-W LTRs act as promoters in directing transcription of HERV-W members, contribute to their tissue-specific and highly diversified expression pattern. Furthermore, leaky transcription originating from adjacent genes plays a role in the transcription initiation of HERV-W psudoelements. It has been reported that HERV-W elements, including ERVWE1 (the so far only known HERV-W locus harboring a gene (env) functionally adopted by the human host to critically participate in placenta biogenesis), can become transactivated in a range of human non-placental cell-lines during exogenous virus infections. Aberrant expression of HERV-W has been associated with human diseases, such as cancer, multiple sclerosis, and schizophrenia. Based on published reports, transcriptional activities of HERV-W appear to be influenced by several mechanisms; binding of transcription factors to LTR promoters and enhancers outside of LTRs, genetic variation and alteration in DNA methylation and histone modification. Emerging mechanistic studies support the notion that HERV-W represents a potential marker or mediator of environmental exposures (e.g., virus infection) in the development of chronic complex diseases.
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Affiliation(s)
- Fang Li
- Department of Basic Medical Science, Changsha Medical University, Changsha, China.,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Håkan Karlsson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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119
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Goff DC, Romero K, Paul J, Mercedes Perez-Rodriguez M, Crandall D, Potkin SG. Biomarkers for drug development in early psychosis: Current issues and promising directions. Eur Neuropsychopharmacol 2016; 26:923-37. [PMID: 27005595 DOI: 10.1016/j.euroneuro.2016.01.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/20/2016] [Accepted: 01/23/2016] [Indexed: 12/14/2022]
Abstract
A major goal of current research in schizophrenia is to understand the biology underlying onset and early progression and to develop interventions that modify these processes. Biomarkers can play a critical role in identifying disease state, factors contributing to underlying progression, as well as predicting and monitoring response to treatment. Once biomarker-based therapeutics are established, biomarkers can guide treatment selection. It is increasingly clear that a wide range of potential biomarkers should be examined in schizophrenia, given the large number of genetic and environmental factors that have been identified as risk factors. New models for analysis of biomarkers are needed that represent the central nervous system as a highly complex, dynamic, and interactive system. Many tools are available with which to study relevant brain chemistry, but most are indirect measures and represent only a small fraction of the potential etiologic factors contributing to the molecular, structural and functional components of schizophrenia. This review represents the work of the International Society for CNS Clinical Trials and Methodology (ISCTM) Biomarkers Working Group. It discusses advantages and disadvantages of different categories of biomarkers and provides a summary of evidence that biomarkers representing inflammation, oxidative stress, endocannabinoids, glucocorticoid, and biogenic amines systems are dysregulated and potentially interactive in early phase schizophrenia. As has been recently demonstrated in several neurodevelopmental and neurodegenerative disorders, a multi-modal, longitudinal strategy involving a diverse array of biomarkers and new approaches to statistical modeling are needed to improve early interventions based on the fuller understanding.
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Affiliation(s)
| | | | - Jeffrey Paul
- Astellas Pharma Global Development, Northbrook, IL, USA
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120
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Starnawska A, Demontis D, McQuillin A, O’Brien NL, Staunstrup NH, Mors O, Nielsen AL, Børglum AD, Nyegaard M. Hypomethylation of FAM63B in bipolar disorder patients. Clin Epigenetics 2016; 8:52. [PMID: 27175219 PMCID: PMC4865008 DOI: 10.1186/s13148-016-0221-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/04/2016] [Indexed: 01/07/2023] Open
Abstract
Bipolar disorder (BD) and schizophrenia (SZ) are known to share common genetic and psychosocial risk factors. A recent epigenome-wide association study performed on blood samples from SZ patients found significant hypomethylation of FAM63B in exon 9. Here, we used iPLEX-based methylation analysis to investigate two CpG sites in FAM63B in blood samples from 459 BD cases and 268 controls. Both sites were significantly hypomethylated in BD cases (lowest p value = 3.94 × 10(-8)). The methylation levels at the two sites were correlated, and no strong correlation was found with nearby single nucleotide polymorphisms (SNPs), suggesting that methylation differences at these sites are not readably picked up by genome-wide association studies. Overall, FAM63B hypomethylation was found in BD patients, thus replicating the initial finding in SZ patients. This study suggests that FAM63B is a shared epigenetic risk gene for the two disorders.
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Affiliation(s)
- Anna Starnawska
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Ditte Demontis
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Andrew McQuillin
- />Molecular Psychiatry Laboratory, Division of Psychiatry, Rockefeller Building, University College London, London, UK
| | - Niamh L. O’Brien
- />Molecular Psychiatry Laboratory, Division of Psychiatry, Rockefeller Building, University College London, London, UK
| | - Nicklas H. Staunstrup
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- />Translational Neuropsychiatry Unit, Aarhus University Hospital, Risskov, Denmark
| | - Ole Mors
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - Anders L. Nielsen
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Anders D. Børglum
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Mette Nyegaard
- />Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, DK- 8000 Aarhus C, Denmark
- />The Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- />Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
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121
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Montano C, Taub MA, Jaffe A, Briem E, Feinberg JI, Trygvadottir R, Idrizi A, Runarsson A, Berndsen B, Gur RC, Moore TM, Perry RT, Fugman D, Sabunciyan S, Yolken RH, Hyde TM, Kleinman JE, Sobell JL, Pato CN, Pato MT, Go RC, Nimgaonkar V, Weinberger DR, Braff D, Gur RE, Fallin MD, Feinberg AP. Association of DNA Methylation Differences With Schizophrenia in an Epigenome-Wide Association Study. JAMA Psychiatry 2016; 73:506-14. [PMID: 27074206 PMCID: PMC6353566 DOI: 10.1001/jamapsychiatry.2016.0144] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IMPORTANCE DNA methylation may play an important role in schizophrenia (SZ), either directly as a mechanism of pathogenesis or as a biomarker of risk. OBJECTIVE To scan genome-wide DNA methylation data to identify differentially methylated CpGs between SZ cases and controls. DESIGN, SETTING, AND PARTICIPANTS Epigenome-wide association study begun in 2008 using DNA methylation levels of 456 513 CpG loci measured on the Infinium HumanMethylation450 array (Illumina) in a consortium of case-control studies for initial discovery and in an independent replication set. Primary analyses used general linear regression, adjusting for age, sex, race/ethnicity, smoking, batch, and cell type heterogeneity. The discovery set contained 689 SZ cases and 645 controls (n = 1334), from 3 multisite consortia: the Consortium on the Genetics of Endophenotypes in Schizophrenia, the Project among African-Americans To Explore Risks for Schizophrenia, and the Multiplex Multigenerational Family Study of Schizophrenia. The replication set contained 247 SZ cases and 250 controls (n = 497) from the Genomic Psychiatry Cohort. MAIN OUTCOMES AND MEASURES Identification of differentially methylated positions across the genome in SZ cases compared with controls. RESULTS Of the 689 case participants in the discovery set, 477 (69%) were men and 258 (37%) were non-African American; of the 645 controls, 273 (42%) were men and 419 (65%) were non-African American. In our replication set, cases/controls were 76% male and 100% non-African American. We identified SZ-associated methylation differences at 923 CpGs in the discovery set (false discovery rate, <0.2). Of these, 625 showed changes in the same direction including 172 with P < .05 in the replication set. Some replicated differentially methylated positions are located in a top-ranked SZ region from genome-wide association study analyses. CONCLUSIONS AND RELEVANCE This analysis identified 172 replicated new associations with SZ after careful correction for cell type heterogeneity and other potential confounders. The overlap with previous genome-wide association study data can provide potential insights into the functional relevance of genetic signals for SZ.
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Affiliation(s)
- Carolina Montano
- Medical Scientist Training Program and Predoctoral Training Program in Human Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland,Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Margaret A. Taub
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Andrew Jaffe
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Eirikur Briem
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jason I. Feinberg
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rakel Trygvadottir
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Adrian Idrizi
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Arni Runarsson
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Birna Berndsen
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ruben C. Gur
- Neuropsychiatry Section, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tyler M. Moore
- Neuropsychiatry Section, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rodney T. Perry
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham
| | - Doug Fugman
- Rutgers University Cell and DNA Repository, Piscataway, New Jersey
| | - Sarven Sabunciyan
- Stanley Division of Developmental Neurovirology, Johns Hopkins, School of Medicine, Baltimore, Maryland
| | - Robert H. Yolken
- Stanley Division of Developmental Neurovirology, Johns Hopkins, School of Medicine, Baltimore, Maryland
| | - Thomas M. Hyde
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Joel E. Kleinman
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - Janet L. Sobell
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Carlos N. Pato
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Michele T. Pato
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine of University of Southern California, Los Angeles
| | - Rodney C. Go
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham
| | | | - Daniel R. Weinberger
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, Maryland
| | - David Braff
- Department of Psychiatry, University of California San Diego School of Medicine, La Jolla,VISN22, Mental Illness Research, Education, and Clinical Center, VA Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Raquel E. Gur
- Neuropsychiatry Section, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Margaret Daniele Fallin
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Andrew P. Feinberg
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, Maryland,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland,Departments of Medicine and Biomedical Engineering, Johns Hopkins University School of Medicine and Whiting School of Engineering, Baltimore, Maryland
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Collier DA, Eastwood BJ, Malki K, Mokrab Y. Advances in the genetics of schizophrenia: toward a network and pathway view for drug discovery. Ann N Y Acad Sci 2016; 1366:61-75. [DOI: 10.1111/nyas.13066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/15/2016] [Accepted: 03/18/2016] [Indexed: 11/28/2022]
Affiliation(s)
- David A. Collier
- Discovery Neuroscience Research; Eli Lilly and Company Ltd; Windlesham Surrey United Kingdom
| | - Brian J. Eastwood
- Discovery Neuroscience Research; Eli Lilly and Company Ltd; Windlesham Surrey United Kingdom
| | - Karim Malki
- Discovery Neuroscience Research; Eli Lilly and Company Ltd; Windlesham Surrey United Kingdom
| | - Younes Mokrab
- Discovery Neuroscience Research; Eli Lilly and Company Ltd; Windlesham Surrey United Kingdom
- Sidra Medical and Research Center; Doha Qatar
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123
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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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124
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Schuch JB, Paixão-Côrtes VR, Friedrich DC, Tovo-Rodrigues L. The contribution of protein intrinsic disorder to understand the role of genetic variants uncovered by autism spectrum disorders exome studies. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:479-91. [PMID: 26892727 DOI: 10.1002/ajmg.b.32431] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 02/04/2016] [Indexed: 01/09/2023]
Abstract
Several autism spectrum disorders (ASD) exome studies suggest that coding single nucleotide variants (SNVs) play an important role on ASD etiology. Usually, the pathogenic effect of missense mutations is estimated through predictors that lose accuracy for those SNVs placed in intrinsically disordered regions of protein. Here, we used bioinformatics tools to investigate the effect of mutations described in ASD published exome studies (549 mutations) in protein disorder, considering post-translational modification, PEST and Molecular Recognition Features (MoRFs) motifs. Schizophrenia and type 2 diabetes (T2D) datasets were created for comparison purposes. The frequency of mutations predicted as disordered was comparable among the three datasets (38.1% in ASD, 35.7% in schizophrenia, 46.4% in T2D). However, the frequency of SNVs predicted to lead a gain or loss of functional sites or change intrinsic disorder tendencies was higher in ASD and schizophrenia than T2D (46.9%, 36.4%, and 23.1%, respectively). The results obtained by SIFT and PolyPhen-2 indicated that 38.9% and 34.4% of the mutations predicted, respectively, as tolerated and benign showed functional alterations in disorder properties. Given the frequency of mutations placed in IDRs and their functional impact, this study suggests that alterations in intrinsic disorder properties might play a role in ASD and schizophrenia etiologies. They should be taken into consideration when researching the pathogenicity of mutations in neurodevelopmental and psychiatric diseases. Finally, mutations with functional alterations in disorder properties must be potential targets for in vitro and in vivo functional studies.
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Affiliation(s)
- Jaqueline Bohrer Schuch
- Department of Genetics, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | | | - Deise C Friedrich
- Department of Cellular and Molecular Biology, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Luciana Tovo-Rodrigues
- Postgraduate Program in Epidemiology, Federal University of Pelotas (UFPel), Pelotas, Rio Grande do Sul, Brazil
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125
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Lai CY, Scarr E, Udawela M, Everall I, Chen WJ, Dean B. Biomarkers in schizophrenia: A focus on blood based diagnostics and theranostics. World J Psychiatry 2016; 6:102-17. [PMID: 27014601 PMCID: PMC4804259 DOI: 10.5498/wjp.v6.i1.102] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/20/2015] [Accepted: 12/17/2015] [Indexed: 02/05/2023] Open
Abstract
Identifying biomarkers that can be used as diagnostics or predictors of treatment response (theranostics) in people with schizophrenia (Sz) will be an important step towards being able to provide personalized treatment. Findings from the studies in brain tissue have not yet been translated into biomarkers that are practical in clinical use because brain biopsies are not acceptable and neuroimaging techniques are expensive and the results are inconclusive. Thus, in recent years, there has been search for blood-based biomarkers for Sz as a valid alternative. Although there are some encouraging preliminary data to support the notion of peripheral biomarkers for Sz, it must be acknowledged that Sz is a complex and heterogeneous disorder which needs to be further dissected into subtype using biological based and clinical markers. The scope of this review is to critically examine published blood-based biomarker of Sz, focusing on possible uses for diagnosis, treatment response, or their relationship with schizophrenia-associated phenotype. We sorted the studies into six categories which include: (1) brain-derived neurotrophic factor; (2) inflammation and immune function; (3) neurochemistry; (4) oxidative stress response and metabolism; (5) epigenetics and microRNA; and (6) transcriptome and proteome studies. This review also summarized the molecules which have been conclusively reported as potential blood-based biomarkers for Sz in different blood cell types. Finally, we further discusses the pitfall of current blood-based studies and suggest that a prediction model-based, Sz specific, blood oriented study design as well as standardize blood collection conditions would be useful for Sz biomarker development.
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126
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Goff D. The Therapeutic Role of d-Cycloserine in Schizophrenia. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 76:39-66. [PMID: 27288073 DOI: 10.1016/bs.apha.2016.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The ketamine model for schizophrenia has led to several therapeutic strategies for enhancing N-methyl d-aspartate (NMDA) receptor activity, including agonists directed at the glycine receptor site and inhibitors of glycine reuptake. Because ketamine may primarily block NMDA receptors on inhibitory interneurons, drugs that reduce glutamate release have also been investigated as a means of countering a deficit in inhibitory input. These approaches have met with some success for the treatment of negative and positive symptoms, but results have not been consistent. An emerging approach with the NMDA partial agonist, d-cycloserine (DCS), aims to enhance plasticity by intermittent treatment. Early trials have demonstrated benefit with intermittent DCS dosing for negative symptoms and memory. When combined with cognitive remediation, intermittent DCS treatment enhanced learning on a practiced auditory discrimination task and when added to cognitive behavioral therapy, DCS improved delusional severity in subjects who received DCS with the first CBT session. These studies require replication, but point toward a promising strategy for the treatment of schizophrenia and other disorders of plasticity.
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Affiliation(s)
- D Goff
- NYU School of Medicine, New York, United States.
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127
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Soto J, Rodriguez-Antolin C, Vallespín E, de Castro Carpeño J, Ibanez de Caceres I. The impact of next-generation sequencing on the DNA methylation-based translational cancer research. Transl Res 2016; 169:1-18.e1. [PMID: 26687736 DOI: 10.1016/j.trsl.2015.11.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/29/2015] [Accepted: 11/14/2015] [Indexed: 01/08/2023]
Abstract
Epigenetics is currently in an exponential phase of growth, constituting one of the most promising fields in science, particularly in cancer research. Impaired epigenetic processes can lead to abnormal gene activity or inactivity, causing cellular disorders that are closely associated with tumor initiation and progression. Thus, there is a pivotal role of massive sequencing techniques for epigenetics, which aim to find novel biomarkers, factors of prognosis and prediction, and targets for achieving personalized treatments. We present a brief description of the evolution of next-generation sequencing technologies and its coupling with DNA methylation analysis techniques, highlighting its future in translational medicine and presenting significant findings in several malignancies. We also expose critical topics related to the implementation of these approaches, which is expected to be affordable for most research centers in the near future.
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Affiliation(s)
- Javier Soto
- Cancer Epigenetics Laboratory, INGEMM, La Paz University Hospital, Madrid, Spain; Biomarkers and Experimental Therapeutics in Cancer, IdiPAZ, Madrid, Spain
| | - Carlos Rodriguez-Antolin
- Cancer Epigenetics Laboratory, INGEMM, La Paz University Hospital, Madrid, Spain; Biomarkers and Experimental Therapeutics in Cancer, IdiPAZ, Madrid, Spain
| | - Elena Vallespín
- Structural and Functional Genomics, INGEMM-IdiPAZ-CIBERER, La Paz University Hospital, Madrid, Spain
| | | | - Inmaculada Ibanez de Caceres
- Cancer Epigenetics Laboratory, INGEMM, La Paz University Hospital, Madrid, Spain; Biomarkers and Experimental Therapeutics in Cancer, IdiPAZ, Madrid, Spain.
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128
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Modai S, Shomron N. Molecular Risk Factors for Schizophrenia. Trends Mol Med 2016; 22:242-253. [DOI: 10.1016/j.molmed.2016.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 01/15/2016] [Accepted: 01/15/2016] [Indexed: 01/02/2023]
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129
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Zhao Y, Castellanos FX. Annual Research Review: Discovery science strategies in studies of the pathophysiology of child and adolescent psychiatric disorders--promises and limitations. J Child Psychol Psychiatry 2016; 57:421-39. [PMID: 26732133 PMCID: PMC4760897 DOI: 10.1111/jcpp.12503] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/17/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND Psychiatric science remains descriptive, with a categorical nosology intended to enhance interobserver reliability. Increased awareness of the mismatch between categorical classifications and the complexity of biological systems drives the search for novel frameworks including discovery science in Big Data. In this review, we provide an overview of incipient approaches, primarily focused on classically categorical diagnoses such as schizophrenia (SZ), autism spectrum disorder (ASD), and attention-deficit/hyperactivity disorder (ADHD), but also reference convincing, if focal, advances in cancer biology, to describe the challenges of Big Data and discovery science, and outline approaches being formulated to overcome existing obstacles. FINDINGS A paradigm shift from categorical diagnoses to a domain/structure-based nosology and from linear causal chains to complex causal network models of brain-behavior relationship is ongoing. This (r)evolution involves appreciating the complexity, dimensionality, and heterogeneity of neuropsychiatric data collected from multiple sources ('broad' data) along with data obtained at multiple levels of analysis, ranging from genes to molecules, cells, circuits, and behaviors ('deep' data). Both of these types of Big Data landscapes require the use and development of robust and powerful informatics and statistical approaches. Thus, we describe Big Data analysis pipelines and the promise and potential limitations in using Big Data approaches to study psychiatric disorders. CONCLUSIONS We highlight key resources available for psychopathological studies and call for the application and development of Big Data approaches to dissect the causes and mechanisms of neuropsychiatric disorders and identify corresponding biomarkers for early diagnosis.
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Affiliation(s)
- Yihong Zhao
- Department of Child and Adolescent Psychiatry, NYU Child Study Center at NYU Langone Medical Center, New York, NY 10016, USA
| | - F. Xavier Castellanos
- Department of Child and Adolescent Psychiatry, NYU Child Study Center at NYU Langone Medical Center, New York, NY 10016, USA,Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
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130
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Walton E, Hass J, Liu J, Roffman JL, Bernardoni F, Roessner V, Kirsch M, Schackert G, Calhoun V, Ehrlich S. Correspondence of DNA Methylation Between Blood and Brain Tissue and Its Application to Schizophrenia Research. Schizophr Bull 2016; 42:406-14. [PMID: 26056378 PMCID: PMC4753587 DOI: 10.1093/schbul/sbv074] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Given the difficulty of procuring human brain tissue, a key question in molecular psychiatry concerns the extent to which epigenetic signatures measured in more accessible tissues such as blood can serve as a surrogate marker for the brain. Here, we aimed (1) to investigate the blood-brain correspondence of DNA methylation using a within-subject design and (2) to identify changes in DNA methylation of brain-related biological pathways in schizophrenia.We obtained paired blood and temporal lobe biopsy samples simultaneously from 12 epilepsy patients during neurosurgical treatment. Using the Infinium 450K methylation array we calculated similarity of blood and brain DNA methylation for each individual separately. We applied our findings by performing gene set enrichment analyses (GSEA) of peripheral blood DNA methylation data (Infinium 27K) of 111 schizophrenia patients and 122 healthy controls and included only Cytosine-phosphate-Guanine (CpG) sites that were significantly correlated across tissues.Only 7.9% of CpG sites showed a statistically significant, large correlation between blood and brain tissue, a proportion that although small was significantly greater than predicted by chance. GSEA analysis of schizophrenia data revealed altered methylation profiles in pathways related to precursor metabolites and signaling peptides.Our findings indicate that most DNA methylation markers in peripheral blood do not reliably predict brain DNA methylation status. However, a subset of peripheral data may proxy methylation status of brain tissue. Restricting the analysis to these markers can identify meaningful epigenetic differences in schizophrenia and potentially other brain disorders.
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Affiliation(s)
- Esther Walton
- Department of Child and Adolescent Psychiatry, Translational Developmental Neuroscience Section, Faculty of Medicine of the TU Dresden, Dresden, Germany;,Department of Psychology, Institute of Psychology, Psychiatry and Neuroscience, King’s College London, London, UK
| | - Johanna Hass
- Department of Child and Adolescent Psychiatry, Translational Developmental Neuroscience Section, Faculty of Medicine of the TU Dresden, Dresden, Germany;,Institute of Tropical Medicine, Eberhard Karls University, Tübingen, Germany
| | - Jingyu Liu
- The Mind Research Network, Albuquerque, NM
| | - Joshua L. Roffman
- MGH/MIT/HMS Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA;,Department of Psychiatry, Massachusetts General Hospital, Boston, MA
| | - Fabio Bernardoni
- Department of Child and Adolescent Psychiatry, Translational Developmental Neuroscience Section, Faculty of Medicine of the TU Dresden, Dresden, Germany
| | - Veit Roessner
- Department of Child and Adolescent Psychiatry, Translational Developmental Neuroscience Section, Faculty of Medicine of the TU Dresden, Dresden, Germany
| | - Matthias Kirsch
- Department of Neurosurgery, Faculty of Medicine of the TU Dresden, Dresden, Germany;,Center for Regenerative Therapies Dresden (CRTD), DFG Research Center and Cluster of Excellence at the TU Dresden, Dresden, Germany
| | - Gabriele Schackert
- Department of Neurosurgery, Faculty of Medicine of the TU Dresden, Dresden, Germany
| | - Vince Calhoun
- The Mind Research Network, Albuquerque, NM;,Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM
| | - Stefan Ehrlich
- Department of Child and Adolescent Psychiatry, Translational Developmental Neuroscience Section, Faculty of Medicine of the TU Dresden, Dresden, Germany; MGH/MIT/HMS Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA; Department of Psychiatry, Massachusetts General Hospital, Boston, MA;
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131
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Wilmot B, Fry R, Smeester L, Musser ED, Mill J, Nigg JT. Methylomic analysis of salivary DNA in childhood ADHD identifies altered DNA methylation in VIPR2. J Child Psychol Psychiatry 2016; 57:152-60. [PMID: 26304033 PMCID: PMC4724325 DOI: 10.1111/jcpp.12457] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND Peripheral epigenetic marks hold promise for understanding psychiatric illness and may represent fingerprints of gene-environment interactions. We conducted an initial examination of CpG methylation variation in children with or without attention-deficit/hyperactivity disorder (ADHD). METHODS Children age 7-12 were recruited, screened, evaluated and assigned to ADHD or non-ADHD groups by defined research criteria. Two independent age-matched samples were examined, a discovery set (n = 92, all boys, half control, half ADHD) and a confirmation set (n = 20, half ADHD, all boys). 5-methylcytosine levels were quantified in salivary DNA using the Illumina 450 K HumanMethylation array. Genes for which multiple probes were nominally significant and had a beta difference of at least 2% were evaluated for biological relevance and prioritized for confirmation and sequence validation. Gene pathways were explored and described. RESULTS Two genes met the criteria for confirmation testing, VIPR2 and MYT1L; both had multiple probes meeting cutoffs and strong biological relevance. Probes on VIPR2 passed FDR correction in the confirmation set and were confirmed through bisulfite sequencing. Enrichment analysis suggested involvement of gene sets or pathways related to inflammatory processes and modulation of monoamine and cholinergic neurotransmission. CONCLUSIONS Although it is unknown to what extent CpG methylation seen in peripheral tissue reflect transcriptomic changes in the brain, these initial results indicate that peripheral DNA methylation markers in ADHD may be promising and suggest targeted hypotheses for future study in larger samples.
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Affiliation(s)
- Beth Wilmot
- Division of Psychology, Oregon Health & Science University, Portland, OR
| | - Rebecca Fry
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC
| | - Lisa Smeester
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC
| | - Erica D. Musser
- Department of Psychology, Florida International University, Miami, FL, USA
| | - Jonathan Mill
- University of Exeter Medical School, Exeter University, Exeter,Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Joel T. Nigg
- Division of Psychology, Oregon Health & Science University, Portland, OR
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132
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Sun YV, Hu YJ. Integrative Analysis of Multi-omics Data for Discovery and Functional Studies of Complex Human Diseases. ADVANCES IN GENETICS 2016; 93:147-90. [PMID: 26915271 DOI: 10.1016/bs.adgen.2015.11.004] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Complex and dynamic networks of molecules are involved in human diseases. High-throughput technologies enable omics studies interrogating thousands to millions of makers with similar biochemical properties (eg, transcriptomics for RNA transcripts). However, a single layer of "omics" can only provide limited insights into the biological mechanisms of a disease. In the case of genome-wide association studies, although thousands of single nucleotide polymorphisms have been identified for complex diseases and traits, the functional implications and mechanisms of the associated loci are largely unknown. Additionally, the genomic variants alone are not able to explain the changing disease risk across the life span. DNA, RNA, protein, and metabolite often have complementary roles to jointly perform a certain biological function. Such complementary effects and synergistic interactions between omic layers in the life course can only be captured by integrative study of multiple molecular layers. Building upon the success in single-omics discovery research, population studies started adopting the multi-omics approach to better understanding the molecular function and disease etiology. Multi-omics approaches integrate data obtained from different omic levels to understand their interrelation and combined influence on the disease processes. Here, we summarize major omics approaches available in population research, and review integrative approaches and methodologies interrogating multiple omic layers, which enhance the gene discovery and functional analysis of human diseases. We seek to provide analytical recommendations for different types of multi-omics data and study designs to guide the emerging multi-omic research, and to suggest improvement of the existing analytical methods.
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Affiliation(s)
- Yan V Sun
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, United States; Department of Biomedical Informatics, School of Medicine, Atlanta, GA, United States
| | - Yi-Juan Hu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, United States
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133
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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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134
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Yugi K, Kubota H, Hatano A, Kuroda S. Trans-Omics: How To Reconstruct Biochemical Networks Across Multiple 'Omic' Layers. Trends Biotechnol 2016; 34:276-290. [PMID: 26806111 DOI: 10.1016/j.tibtech.2015.12.013] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 12/17/2022]
Abstract
We propose 'trans-omic' analysis for reconstructing global biochemical networks across multiple omic layers by use of both multi-omic measurements and computational data integration. We introduce technologies for connecting multi-omic data based on prior knowledge of biochemical interactions and characterize a biochemical trans-omic network by concepts of a static and dynamic nature. We introduce case studies of metabolism-centric trans-omic studies to show how to reconstruct a biochemical trans-omic network by connecting multi-omic data and how to analyze it in terms of the static and dynamic nature. We propose a trans-ome-wide association study (trans-OWAS) connecting phenotypes with trans-omic networks that reflect both genetic and environmental factors, which can characterize several complex lifestyle diseases as breakdowns in the trans-omic system.
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Affiliation(s)
- Katsuyuki Yugi
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan; PRESTO, Japan Science and Technology Agency, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hiroyuki Kubota
- Division of Integrated Omics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan; PRESTO, Japan Science and Technology Agency, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Atsushi Hatano
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shinya Kuroda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan; CREST, Japan Science and Technology Agency, Bunkyo-ku, Tokyo 113-0033, Japan.
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135
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Sparrow S, Manning JR, Cartier J, Anblagan D, Bastin ME, Piyasena C, Pataky R, Moore EJ, Semple SI, Wilkinson AG, Evans M, Drake AJ, Boardman JP. Epigenomic profiling of preterm infants reveals DNA methylation differences at sites associated with neural function. Transl Psychiatry 2016; 6:e716. [PMID: 26784970 PMCID: PMC5068883 DOI: 10.1038/tp.2015.210] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 12/13/2022] Open
Abstract
DNA methylation (DNAm) plays a determining role in neural cell fate and provides a molecular link between early-life stress and neuropsychiatric disease. Preterm birth is a profound environmental stressor that is closely associated with alterations in connectivity of neural systems and long-term neuropsychiatric impairment. The aims of this study were to examine the relationship between preterm birth and DNAm, and to investigate factors that contribute to variance in DNAm. DNA was collected from preterm infants (birth<33 weeks gestation) and healthy controls (birth>37 weeks), and a genome-wide analysis of DNAm was performed; diffusion magnetic resonance imaging (dMRI) data were acquired from the preterm group. The major fasciculi were segmented, and fractional anisotropy, mean diffusivity and tract shape were calculated. Principal components (PC) analysis was used to investigate the contribution of MRI features and clinical variables to variance in DNAm. Differential methylation was found within 25 gene bodies and 58 promoters of protein-coding genes in preterm infants compared with controls; 10 of these have neural functions. Differences detected in the array were validated with pyrosequencing. Ninety-five percent of the variance in DNAm in preterm infants was explained by 23 PCs; corticospinal tract shape associated with 6th PC, and gender and early nutritional exposure associated with the 7th PC. Preterm birth is associated with alterations in the methylome at sites that influence neural development and function. Differential methylation analysis has identified several promising candidate genes for understanding the genetic/epigenetic basis of preterm brain injury.
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Affiliation(s)
- S Sparrow
- MRC Centre for Reproductive Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, UK
| | - J R Manning
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - J Cartier
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - D Anblagan
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - M E Bastin
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - C Piyasena
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - R Pataky
- MRC Centre for Reproductive Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, UK
| | - E J Moore
- MRC Centre for Reproductive Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, UK
| | - S I Semple
- Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, UK
| | | | - M Evans
- Department of Pathology, NHS Lothian, Edinburgh, UK
| | - A J Drake
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - J P Boardman
- MRC Centre for Reproductive Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, UK,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK,MRC Centre for Reproductive Health, University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Room W1.26, Edinburgh EH16 4TJ, UK. E-mail:
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136
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High density methylation QTL analysis in human blood via next-generation sequencing of the methylated genomic DNA fraction. Genome Biol 2015; 16:291. [PMID: 26699738 PMCID: PMC4699364 DOI: 10.1186/s13059-015-0842-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/20/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Genetic influence on DNA methylation is potentially an important mechanism affecting individual differences in humans. We use next-generation sequencing to assay blood DNA methylation at approximately 4.5 million loci, each comprising 2.9 CpGs on average, in 697 normal subjects. Methylation measures at each locus are tested for association with approximately 4.5 million single nucleotide polymorphisms (SNPs) to exhaustively screen for methylation quantitative trait loci (meQTLs). RESULTS Using stringent false discovery rate control, 15 % of methylation sites show genetic influence. Most meQTLs are local, where the associated SNP and methylation site are in close genomic proximity. Distant meQTLs and those spanning different chromosomes are less common. Most local meQTLs encompass common SNPs that alter CpG sites (CpG-SNPs). Local meQTLs encompassing CpG-SNPs are enriched in regions of inactive chromatin in blood cells. In contrast, local meQTLs lacking CpG-SNPs are enriched in regions of active chromatin and transcription factor binding sites. Of 393 local meQTLs that overlap disease-associated regions from genome-wide studies, a high percentage encompass common CpG-SNPs. These meQTLs overlap active enhancers, differentiating them from CpG-SNP meQTLs in inactive chromatin. CONCLUSIONS Genetic influence on the human blood methylome is common, involves several heterogeneous processes and is predominantly dependent on local sequence context at the meQTL site. Most meQTLs involve CpG-SNPs, while sequence-dependent effects on chromatin binding are also important in regions of active chromatin. An abundance of local meQTLs resulting from methylation of CpG-SNPs in inactive chromatin suggests that many meQTLs lack functional consequence. Integrating meQTL and Roadmap Epigenomics data could assist fine-mapping efforts.
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137
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Smart C, Strathdee G, Watson S, Murgatroyd C, McAllister-Williams RH. Early life trauma, depression and the glucocorticoid receptor gene--an epigenetic perspective. Psychol Med 2015; 45:3393-3410. [PMID: 26387521 DOI: 10.1017/s0033291715001555] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Hopes to identify genetic susceptibility loci accounting for the heritability seen in unipolar depression have not been fully realized. Family history remains the 'gold standard' for both risk stratification and prognosis in complex phenotypes such as depression. Meanwhile, the physiological mechanisms underlying life-event triggers for depression remain opaque. Epigenetics, comprising heritable changes in gene expression other than alterations of the nucleotide sequence, may offer a way to deepen our understanding of the aetiology and pathophysiology of unipolar depression and optimize treatments. A heuristic target for exploring the relevance of epigenetic changes in unipolar depression is the hypothalamic-pituitary-adrenal (HPA) axis. The glucocorticoid receptor (GR) gene (NR3C1) has been found to be susceptible to epigenetic modification, specifically DNA methylation, in the context of environmental stress such as early life trauma, which is an established risk for depression later in life. METHOD In this paper we discuss the progress that has been made by studies that have investigated the relationship between depression, early trauma, the HPA axis and the NR3C1 gene. Difficulties with the design of these studies are also explored. RESULTS Future efforts will need to comprehensively address epigenetic natural histories at the population, tissue, cell and gene levels. The complex interactions between the epigenome, genome and environment, as well as ongoing nosological difficulties, also pose significant challenges. CONCLUSIONS The work that has been done so far is nevertheless encouraging and suggests potential mechanistic and biomarker roles for differential DNA methylation patterns in NR3C1 as well as novel therapeutic targets.
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Affiliation(s)
- C Smart
- Institute of Neuroscience,Newcastle University,Newcastle upon Tyne,UK
| | - G Strathdee
- Northern Institute for Cancer Research,Newcastle University,Newcastle upon Tyne,UK
| | - S Watson
- Institute of Neuroscience,Newcastle University,Newcastle upon Tyne,UK
| | - C Murgatroyd
- School of Healthcare Science,Manchester Metropolitan University,Manchester,UK
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138
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Abdolmaleky HM, Pajouhanfar S, Faghankhani M, Joghataei MT, Mostafavi A, Thiagalingam S. Antipsychotic drugs attenuate aberrant DNA methylation of DTNBP1 (dysbindin) promoter in saliva and post-mortem brain of patients with schizophrenia and Psychotic bipolar disorder. Am J Med Genet B Neuropsychiatr Genet 2015; 168:687-96. [PMID: 26285059 DOI: 10.1002/ajmg.b.32361] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 07/31/2015] [Indexed: 12/13/2022]
Abstract
Due to the lack of genetic association between individual genes and schizophrenia (SCZ) pathogenesis, the current consensus is to consider both genetic and epigenetic alterations. Here, we report the examination of DNA methylation status of DTNBP1 promoter region, one of the most credible candidate genes affected in SCZ, assayed in saliva and post-mortem brain samples. The Illumina DNA methylation profiling and bisulfite sequencing of representative samples were used to identify methylation status of the DTNBP1 promoter region. Quantitative methylation specific PCR (qMSP) was employed to assess methylation of DTNBP1 promoter CpGs flanking a SP1 binding site in the saliva of SCZ patients, their first-degree relatives and control subjects (30, 15, and 30/group, respectively) as well as in post-mortem brains of patients with SCZ and bipolar disorder (BD) versus controls (35/group). qRT-PCR was used to assess DTNBP1 expression. We found DNA hypermethylation of DTNBP1 promoter in the saliva of SCZ patients (∼12.5%, P = 0.036), particularly in drug-naïve patients (∼20%, P = 0.011), and a trend toward hypermethylation in their first-degree relatives (P = 0.085) versus controls. Analysis of post-mortem brain samples revealed an inverse correlation between DTNBP1 methylation and expression, and normalization of this epigenetic change by classic antipsychotic drugs. Additionally, BD patients with psychotic depression exhibited higher degree of methylation versus other BD patients (∼80%, P = 0.025). DTNBP1 promoter DNA methylation may become a key element in a panel of biomarkers for diagnosis, prevention, or therapy in SCZ and at risk individuals pending confirmatory studies with larger sample sizes to attain a higher degree of significance.
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Affiliation(s)
- Hamid M Abdolmaleky
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, Massachusetts.,Mental Health Research Center, Department of Psychiatry, Iran University of Medical Sciences, Tehran, Iran
| | - Sara Pajouhanfar
- Mental Health Research Center, Department of Psychiatry, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mohammad Taghi Joghataei
- Cellular and Molecular Research Center, Department of Anatomy, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ashraf Mostafavi
- Arian Salamat Counselling and Nursing Services Centre, Tehran, Iran
| | - Sam Thiagalingam
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, Massachusetts.,Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts
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139
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Pidsley R, Viana J, Hannon E, Spiers H, Troakes C, Al-Saraj S, Mechawar N, Turecki G, Schalkwyk LC, Bray NJ, Mill J. Methylomic profiling of human brain tissue supports a neurodevelopmental origin for schizophrenia. Genome Biol 2015; 15:483. [PMID: 25347937 PMCID: PMC4262979 DOI: 10.1186/s13059-014-0483-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Schizophrenia is a severe neuropsychiatric disorder that is hypothesized to result from disturbances ine arly brain development. There is mounting evidence to support a role for developmentally regulated epigenetic variation in the molecular etiology of the disorder. Here, we describe a systematic study of schizophrenia-associated methylomic variation in the adult brain and its relationship to changes in DNA methylation across human fetal brain development. RESULTS We profile methylomic variation in matched prefrontal cortex and cerebellum brain tissue from schizophrenia patients and controls, identifying disease-associated differential DNA methylation at multiple loci,particularly in the prefrontal cortex, and confirming these differences in an independent set of adult brain samples.Our data reveal discrete modules of co-methylated loci associated with schizophrenia that are enriched for genes involved in neurodevelopmental processes and include loci implicated by genetic studies of the disorder. Methylomic data from human fetal cortex samples, spanning 23 to 184 days post-conception, indicates that schizophrenia-associated differentially methylated positions are significantly enriched for loci at which DNA methylation is dynamically altered during human fetal brain development. CONCLUSIONS Our data support the hypothesis that schizophrenia has an important early neurodevelopmental component, and suggest that epigenetic mechanisms may mediate these effects.
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Affiliation(s)
- Ruth Pidsley
- Institute of Psychiatry, King’s College London, London, SE5 8AF, UK
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140
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Nestler EJ, Peña CJ, Kundakovic M, Mitchell A, Akbarian S. Epigenetic Basis of Mental Illness. Neuroscientist 2015; 22:447-63. [PMID: 26450593 DOI: 10.1177/1073858415608147] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Psychiatric disorders are complex multifactorial illnesses involving chronic alterations in neural circuit structure and function as well as likely abnormalities in glial cells. While genetic factors are important in the etiology of most mental disorders, the relatively high rates of discordance among identical twins, particularly for depression and other stress-related syndromes, clearly indicate the importance of additional mechanisms. Environmental factors such as stress are known to play a role in the onset of these illnesses. Exposure to such environmental insults induces stable changes in gene expression, neural circuit function, and ultimately behavior, and these maladaptations appear distinct between developmental versus adult exposures. Increasing evidence indicates that these sustained abnormalities are maintained by epigenetic modifications in specific brain regions. Indeed, transcriptional dysregulation and the aberrant epigenetic regulation that underlies this dysregulation is a unifying theme in psychiatric disorders. Here, we provide a progress report of epigenetic studies of the three major psychiatric syndromes, depression, schizophrenia, and bipolar disorder. We review the literature derived from animal models of these disorders as well as from studies of postmortem brain tissue from human patients. While epigenetic studies of mental illness remain at early stages, understanding how environmental factors recruit the epigenetic machinery within specific brain regions to cause lasting changes in disease susceptibility and pathophysiology is revealing new insight into the etiology and treatment of these conditions.
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Affiliation(s)
- Eric J Nestler
- Departments of Neuroscience and Psychiatry, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Catherine J Peña
- Departments of Neuroscience and Psychiatry, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Marija Kundakovic
- Departments of Neuroscience and Psychiatry, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amanda Mitchell
- Departments of Neuroscience and Psychiatry, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Schahram Akbarian
- Departments of Neuroscience and Psychiatry, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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141
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Shabalin AA, Aberg KA, van den Oord EJCG. Candidate gene methylation studies are at high risk of erroneous conclusions. Epigenomics 2015; 7:13-5. [PMID: 25687462 DOI: 10.2217/epi.14.70] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Andrey A Shabalin
- Center for Biomarker Research & Personalized Medicine, Virginia Common-wealth University, PO Box 980533, Richmond, VA 23298, USA
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142
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Aberg KA, Xie L, Chan RF, Zhao M, Pandey AK, Kumar G, Clark SL, van den Oord EJCG. Evaluation of Methyl-Binding Domain Based Enrichment Approaches Revisited. PLoS One 2015; 10:e0132205. [PMID: 26177298 PMCID: PMC4503759 DOI: 10.1371/journal.pone.0132205] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/13/2015] [Indexed: 11/28/2022] Open
Abstract
Methyl-binding domain (MBD) enrichment followed by deep sequencing (MBD-seq), is a robust and cost efficient approach for methylome-wide association studies (MWAS). MBD-seq has been demonstrated to be capable of identifying differentially methylated regions, detecting previously reported robust associations and producing findings that replicate with other technologies such as targeted pyrosequencing of bisulfite converted DNA. There are several kits commercially available that can be used for MBD enrichment. Our previous work has involved MethylMiner (Life Technologies, Foster City, CA, USA) that we chose after careful investigation of its properties. However, in a recent evaluation of five commercially available MBD-enrichment kits the performance of the MethylMiner was deemed poor. Given our positive experience with MethylMiner, we were surprised by this report. In an attempt to reproduce these findings we here have performed a direct comparison of MethylMiner with MethylCap (Diagenode Inc, Denville, NJ, USA), the best performing kit in that study. We find that both MethylMiner and MethylCap are two well performing MBD-enrichment kits. However, MethylMiner shows somewhat better enrichment efficiency and lower levels of background “noise”. In addition, for the purpose of MWAS where we want to investigate the majority of CpGs, we find MethylMiner to be superior as it allows tailoring the enrichment to the regions where most CpGs are located. Using targeted bisulfite sequencing we confirmed that sites where methylation was detected by either MethylMiner or by MethylCap indeed were methylated.
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Affiliation(s)
- Karolina A Aberg
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Linying Xie
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Robin F Chan
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Min Zhao
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Ashutosh K Pandey
- Center for Integrative and Translational Genomics and Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States of America
| | - Gaurav Kumar
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Shaunna L Clark
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Edwin J C G van den Oord
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, United States of America
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143
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Sabunciyan S, Maher B, Bahn S, Dickerson F, Yolken RH. Association of DNA Methylation with Acute Mania and Inflammatory Markers. PLoS One 2015; 10:e0132001. [PMID: 26147665 PMCID: PMC4492496 DOI: 10.1371/journal.pone.0132001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/09/2015] [Indexed: 11/18/2022] Open
Abstract
In order to determine whether epigenetic changes specific to the manic mood state can be detected in peripheral blood samples we assayed DNA methylation levels genome-wide in serum samples obtained from 20 patients hospitalized for mania and 20 unaffected controls using the Illumina 450K methylation arrays. We identified a methylation locus in the CYP11A1 gene, which is regulated by corticotropin, that is hypo-methylated in individuals hospitalized for mania compared with unaffected controls. DNA methylation levels at this locus appear to be state related as levels in follow-up samples collected from mania patients six months after hospitalization were similar to those observed in controls. In addition, we found that methylation levels at the CYP11A1 locus were significantly correlated with three inflammatory markers in serum in acute mania cases but not in unaffected controls. We conclude that mania is associated with alterations in levels of DNA methylation and inflammatory markers. Since epigenetic markers are potentially malleable, a better understanding of the role of epigenetics may lead to new methods for the prevention and treatment of mood disorders.
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Affiliation(s)
- Sarven Sabunciyan
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail: (SS); (RHY)
| | - Brion Maher
- Department of Mental Health, Johns Hopkins School of Public Health, Baltimore, MD, United States of America
| | - Sabine Bahn
- Department of Chemical Engineering & Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Faith Dickerson
- Sheppard Pratt Health System, Baltimore, MD, United States of America
| | - Robert H. Yolken
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail: (SS); (RHY)
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144
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Clark SL, Aberg KA, Nerella S, Kumar G, McClay JL, Chen W, Xie LY, Harada A, Shabalin AA, Gao G, Bergen SE, Hultman CM, Magnusson PKE, Sullivan PF, van den Oord EJCG. Combined Whole Methylome and Genomewide Association Study Implicates CNTN4 in Alcohol Use. Alcohol Clin Exp Res 2015; 39:1396-405. [PMID: 26146898 DOI: 10.1111/acer.12790] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/26/2015] [Indexed: 12/18/2022]
Abstract
BACKGROUND Methylome-wide association (MWAS) studies present a new way to advance the search for biological correlates for alcohol use. A challenge with methylation studies of alcohol involves the causal direction of significant methylation-alcohol associations. One way to address this issue is to combine MWAS data with genomewide association study (GWAS) data. METHODS Here, we combined MWAS and GWAS results for alcohol use from 619 individuals. Our MWAS data were generated by next-generation sequencing of the methylated genomic DNA fraction, producing over 60 million reads per subject to interrogate methylation levels at ~27 million autosomal CpG sites in the human genome. Our GWAS included 5,571,786 single nucleotide polymorphisms (SNPs) imputed with 1000 Genomes. RESULTS When combining the MWAS and GWAS data, our top finding was a region in an intron of CNTN4 (p = 2.55 × 10(-8) ), located between chr3: 2,555,403 and 2,555,524, encompassing SNPs rs1382874 and rs1382875. This finding was then replicated in an independent sample of 730 individuals. We used bisulfite pyrosequencing to measure methylation and found significant association with regular alcohol use in the same direction as the MWAS (p = 0.021). Rs1382874 and rs1382875 were genotyped and found to be associated in the same direction as the GWAS (p = 0.008 and p = 0.009). After integrating the MWAS and GWAS findings from the replication sample, we replicated our combined analysis finding (p = 0.0017) in CNTN4. CONCLUSIONS Through combining methylation and SNP data, we have identified CNTN4 as a risk factor for regular alcohol use.
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Affiliation(s)
- Shaunna L Clark
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Karolina A Aberg
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Srilaxmi Nerella
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Gaurav Kumar
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Joseph L McClay
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Wenan Chen
- Department of Biostatistics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Linying Y Xie
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Aki Harada
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Andrey A Shabalin
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
| | - Guimin Gao
- Department of Biostatistics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Sarah E Bergen
- Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Christina M Hultman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Patrik K E Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Patrick F Sullivan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Edwin J C G van den Oord
- Center for Biomarker Research and Precision Medicine, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia
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145
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Abstract
Schizophrenia is a major psychiatric disorder that lacks a unifying neuropathology, while currently available pharmacological treatments provide only limited benefits to many patients. This review will discuss how the field of neuroepigenetics could contribute to advancements of the existing knowledge on the neurobiology and treatment of psychosis. Genome-scale mapping of DMA methylation, histone modifications and variants, and chromosomal loopings for promoter-enhancer interactions and other epigenetic determinants of genome organization and function are likely to provide important clues about mechanisms contributing to dysregulated expression of synaptic and metabolic genes in schizophrenia brain, including the potential links to the underlying genetic risk architecture and environmental exposures. In addition, studies in animal models are providing a rapidly increasing list of chromatin-regulatory mechanisms with significant effects on cognition and complex behaviors, thereby pointing to the therapeutic potential of epigenetic drug targets in the nervous system.
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Affiliation(s)
- Schahram Akbarian
- Department of Psychiatry, Friedman Brain Institute Icahn School of Medicine at Mount Sinai, New York, USA
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146
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Abstract
DNA methylation is a chemical modification that occurs predominantly on CG dinucleotides in mammalian genomes. However, recent studies have revealed that non-CG methylation (mCH) is abundant and nonrandomly distributed in the genomes of pluripotent cells and brain cells, and is present at lower levels in many other human cells and tissues. Surprisingly, mCH in pluripotent cells is distinct from that in brain cells in terms of sequence specificity and association with transcription, indicating the existence of different mCH pathways. In addition, several recent studies have begun to reveal the biological significance of mCH in diverse cellular processes. In reprogrammed somatic cells, mCH marks megabase-scale regions that have failed to revert to the pluripotent epigenetic state. In myocytes, promoter mCH accumulation is associated with the transcriptional response to environmental factors. In brain cells, mCH accumulates during the establishment of neural circuits and is associated with Rett syndrome. In this review, we summarize the current understanding of mCH and its possible functional consequences in different biological contexts.
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Affiliation(s)
- Yupeng He
- Bioinformatics Program, University of California, San Diego, La Jolla, California 92093
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147
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Abdolmaleky HM, Zhou JR, Thiagalingam S. An update on the epigenetics of psychotic diseases and autism. Epigenomics 2015; 7:427-49. [DOI: 10.2217/epi.14.85] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The examination of potential roles of epigenetic alterations in the pathogenesis of psychotic diseases have become an essential alternative in recent years as genetic studies alone are yet to uncover major gene(s) for psychosis. Here, we describe the current state of knowledge from the gene-specific and genome-wide studies of postmortem brain and blood cells indicating that aberrant DNA methylation, histone modifications and dysregulation of micro-RNAs are linked to the pathogenesis of mental diseases. There is also strong evidence supporting that all classes of psychiatric drugs modulate diverse features of the epigenome. While comprehensive environmental and genetic/epigenetic studies are uncovering the origins, and the key genes/pathways affected in psychotic diseases, characterizing the epigenetic effects of psychiatric drugs may help to design novel therapies in psychiatry.
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Affiliation(s)
- Hamid Mostafavi Abdolmaleky
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, MA 02118, USA
- Nutrition/Metabolism Laboratory at Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Jin-Rong Zhou
- Nutrition/Metabolism Laboratory at Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Sam Thiagalingam
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Pathology & Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
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148
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Zhang Y, Chang Z, Chen J, Ling Y, Liu X, Feng Z, Chen C, Xia M, Zhao X, Ying W, Qing X, Li G, Zhang C. Methylation of the tryptophan hydroxylase‑2 gene is associated with mRNA expression in patients with major depression with suicide attempts. Mol Med Rep 2015; 12:3184-90. [PMID: 25955598 DOI: 10.3892/mmr.2015.3748] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 04/09/2015] [Indexed: 11/06/2022] Open
Abstract
Tryptophan hydroxylase-2 (TPH2) contributes to alterations in the function of neuronal serotonin (5-HT), which are associated with various psychopathologies, including major depressive disorder (MDD) or suicidal behavior. The methylation of a single CpG site in the promoter region of TPH2 affects gene expression. Suicide and MDD are strongly associated and genetic factors are at least partially responsible for the variability in suicide risk. The aim of the present study was to investigate whether variations in TPH2 methylation in peripheral blood samples may predispose patients with MDD to suicide attempts. TPH2 mRNA expression levels differed significantly between 50 patients with MDD who had attempted suicide (MDD + suicide group) and 75 control patients with MDD (MDD group); TPH2 expression levels were significantly decreased (P=0.0005) in the patients who had attempted suicide. Furthermore, the frequency of TPH2 methylation was 36.0% in the MDD + suicide group, while it was 13.0% in the MDD group. The results of the present study demonstrated that methylation in the promoter region of TPH2 significantly affected the mRNA expression levels of TPH2, thus suggesting that methylation of the TPH2 promoter may silence TPH2 mRNA expression in MDD patients with or without suicidal behavior. In addition, there was a significant correlation between the methylation status of the TPH2 promoter and depression, hopelessness and cognitive impairment in the MDD + suicide group. In conclusion, the present study demonstrated that TPH2 expression was regulated by DNA methylation of the TPH2 promoter region in patients with MDD.
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Affiliation(s)
- Yuqi Zhang
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Zaohuo Chang
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Jionghua Chen
- Department of Brain, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, Jiangsu 210028, P.R. China
| | - Yang Ling
- Clinical Oncology Laboratory, Changzhou Cancer Hospital of Soochow University, Changzhou, Jiangsu 213002, P.R. China
| | - Xiaowei Liu
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Zhang Feng
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Caixia Chen
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Minghua Xia
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Xingfu Zhao
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Wang Ying
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Xu Qing
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Guilin Li
- Department of Geriatric Psychiatry, Wuxi Psychiatric Hospital, Nanjing Medical University, Wuxi, Jiangsu 214151, P.R. China
| | - Changsong Zhang
- Clinical Oncology Laboratory, Changzhou Cancer Hospital of Soochow University, Changzhou, Jiangsu 213002, P.R. China
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149
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Abstract
PURPOSE OF REVIEW Since decades immunological aberrancies have been reported in schizophrenia patients. As schizophrenia represents a heterogenous disorder with a variety of clinical manifestations, complex interactions between the immune system in the brain might have important etiological implications. RECENT FINDINGS Recent findings of altered expression of immune-related genes, changes of peripheral and central cytokines, antibodies and immune cells point toward dysbalanced immune response processes in schizophrenia. SUMMARY Based on immunogenetic factors, immune dysfunctions caused by infections, increased autoimmune reactivity and low-grade inflammatory processes in the periphery as well as in central nervous system may affect neurobiological circuits including changed neurotransmitter metabolisms contributing to pathophysiological alterations in schizophrenia. These immunological abnormalities might provide tools for better diagnostic characterization of this heterogenous disease and on the other side, they may also support the development of immune-related therapeutic strategies.
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150
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Morishita H, Kundakovic M, Bicks L, Mitchell A, Akbarian S. Interneuron epigenomes during the critical period of cortical plasticity: Implications for schizophrenia. Neurobiol Learn Mem 2015; 124:104-10. [PMID: 25849095 DOI: 10.1016/j.nlm.2015.03.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 03/23/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
Schizophrenia, a major psychiatric disorder defined by delusions and hallucinations, among other symptoms, often with onset in early adulthood, is potentially associated with molecular and cellular alterations in parvalbumin-expressing fast spiking interneurons and other constituents of the cortical inhibitory GABAergic circuitry. The underlying mechanisms, including the role of disease-associated risk factors operating in adolescence such as drug abuse and social stressors, remain incompletely understood. Here, we summarize emerging findings from animal models, highlighting the ability of parvalbuminergic interneurons (PVI) to induce, during the juvenile period, long-term plastic changes in prefrontal and visual cortex, thereby altering perception, cognition and behavior in the adult. Of note, molecular alterations in PVI from subjects with schizophrenia, including downregulated expression of a subset of GABAergic genes, have also been found in juvenile stress models of the disorder. Some of the transcriptional alterations observed in schizophrenia postmortem brain could be linked to changes in the epigenetic architecture of GABAergic gene promoters, including dysregulated DNA methylation, histone modification patterns and disruption of promoter-enhancer interactions at site of chromosomal loop formations. Therefore, we predict that, in the not-to-distant future, PVI- and other cell-type specific epigenomic mappings in the animal model and human brain will provide novel insights into the pathophysiology of schizophrenia and related psychotic diseases, including the role of cortical GABAergic circuitry in shaping long-term plasticity and cognitive function of the cerebral cortex.
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Affiliation(s)
- Hirofumi Morishita
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, United States; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States; Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, United States; Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, United States.
| | - Marija Kundakovic
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, United States; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, United States
| | - Lucy Bicks
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, United States; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, United States
| | - Amanda Mitchell
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, United States; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, United States
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, United States; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, United States.
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