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Polakkattil BK, Vellichirammal NN, Nair IV, Nair CM, Banerjee M. Methylome-wide and meQTL analysis helps to distinguish treatment response from non-response and pathogenesis markers in schizophrenia. Front Psychiatry 2024; 15:1297760. [PMID: 38516266 PMCID: PMC10954811 DOI: 10.3389/fpsyt.2024.1297760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/06/2024] [Indexed: 03/23/2024] Open
Abstract
Schizophrenia is a complex condition with entwined genetic and epigenetic risk factors, posing a challenge to disentangle the intermixed pathological and therapeutic epigenetic signatures. To resolve this, we performed 850K methylome-wide and 700K genome-wide studies on the same set of schizophrenia patients by stratifying them into responders, non-responders, and drug-naïve patients. The key genes that signified the response were followed up using real-time gene expression studies to understand the effect of antipsychotics at the gene transcription level. The study primarily implicates hypermethylation in therapeutic response and hypomethylation in the drug-non-responsive state. Several differentially methylated sites and regions colocalized with the schizophrenia genome-wide association study (GWAS) risk genes and variants, supporting the convoluted gene-environment association. Gene ontology and protein-protein interaction (PPI) network analyses revealed distinct patterns that differentiated the treatment response from drug resistance. The study highlights the strong involvement of several processes related to nervous system development, cell adhesion, and signaling in the antipsychotic response. The ability of antipsychotic medications to alter the pathology by modulating gene expression or methylation patterns is evident from the general increase in the gene expression of response markers and histone modifiers and the decrease in class II human leukocyte antigen (HLA) genes following treatment with varying concentrations of medications like clozapine, olanzapine, risperidone, and haloperidol. The study indicates a directional overlap of methylation markers between pathogenesis and therapeutic response, thereby suggesting a careful distinction of methylation markers of pathogenesis from treatment response. In addition, there is a need to understand the trade-off between genetic and epigenetic observations. It is suggested that methylomic changes brought about by drugs need careful evaluation for their positive effects on pathogenesis, course of disease progression, symptom severity, side effects, and refractoriness.
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Affiliation(s)
- Binithamol K. Polakkattil
- Human Molecular Genetics Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
- Research Center, University of Kerala, Thiruvananthapuram, Kerala, India
| | - Neetha N. Vellichirammal
- Human Molecular Genetics Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Indu V. Nair
- Mental Health Centre, Thiruvananthapuram, Kerala, India
| | | | - Moinak Banerjee
- Human Molecular Genetics Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
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Sun Z, Li M, Dong C, Mei S. Clinical characteristics of infantile haemangioma in twins: a retrospective study. BMC Pediatr 2024; 24:111. [PMID: 38350912 PMCID: PMC10863135 DOI: 10.1186/s12887-024-04602-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Infantile hemangioma is one of the most common benign soft tissue tumors in infants. The pathogenesis of infantile hemangioma remains unclear and twin studies regarding its incidence may help clarify disease pathogenesis. Thus, this study aimed to analyze the clinical characteristics of infantile hemangioma in twin patients and discuss its clinical incidence. METHODS We retrospectively analyzed the data of 83 pairs of twins with infantile hemangioma admitted to the Guangdong Provincial Women and Children Hospital and Henan Provincial People's Hospital between May 2016 and May 2022. Thirty-one pairs of twins among whom both developed infantile hemangioma and 52 pairs of twins among whom only one twin was affected were included. Analysis was performed using the Spearman correlation. Additionally, we analyzed the influence of factors such as sex, twin zygosity, preterm birth, birth weight, and assisted reproduction on the clinical characteristics of twins. RESULTS We observed that disease occurrence in both twins correlated with assisted reproduction (χ2 = 13. 102, P < 0.05) and preterm birth (χ2 = 36.523, P < 0.05). Twin zygosity (χ2 = 0.716, P > 0.05) and total birth weight of twins (t=-3.369, P > 0.05) were not correlated with infantile hemangioma. However, among twins, the ones with lesser birth weight were more likely to develop infantile hemangioma. CONCLUSIONS The clinical characteristics of infantile hemangioma in twins were consistent with their epidemiological characteristics. Female sex, preterm birth, less birth weight, and assisted reproduction increased the probability of morbidity in both twins. Analysis of the characteristics of infantile hemangioma in twins may assist further research and clinical treatment.
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Affiliation(s)
- Zhengwei Sun
- Department of Interventional Radiology and Hemangioma, Guangdong Province Woman and Children Hospital, Guangzhou, People's Republic of China
| | - Miaomiao Li
- Department of Hemangioma and Vascular Malformation, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China.
| | - Changxian Dong
- Department of Hemangioma and Vascular Malformation, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China
| | - Shiwei Mei
- Department of Interventional Radiology and Hemangioma, Guangdong Province Woman and Children Hospital, Guangzhou, People's Republic of China
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Singh M, Saxena S, Mohan KN. DNMT1 downregulation as well as its overexpression distinctly affect mostly overlapping genes implicated in schizophrenia, autism spectrum, epilepsy, and bipolar disorders. Front Mol Neurosci 2023; 16:1275697. [PMID: 38125006 PMCID: PMC10731955 DOI: 10.3389/fnmol.2023.1275697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
Data on schizophrenia (SZ), epilepsy (EPD) and bipolar disorders (BPD) suggested an association of DNMT1 overexpression whereas certain variants of the gene were predicted to result in its increased expression in autism spectrum disorder (ASD). In addition, loss of DNMT1 in frontal cortex resulted in behavioral abnormalities in mice. Here we investigated the effects of increased as well as lack of DNMT1 expression using Dnmt1tet/tet neurons as a model for abnormal neurogenesis and 10,861 genes showing transcript level dysregulation in datasets from the four disorders. In case of overexpression, 3,211 (∼ 30%) genes were dysregulated, affecting pathways involved in neurogenesis, semaphorin signaling, ephrin receptor activity, etc. A disproportionately higher proportion of dysregulated genes were associated with epilepsy. When transcriptome data of Dnmt1tet/tet neurons treated with doxycycline that downregulated DNMT1 was used, 3,356 genes (∼31%) were dysregulated with a significant proportion involved in pathways similar to those in untreated cells. Both conditions resulted in ∼68% of dysregulated genes wherein a majority showed similar patterns of transcript level changes. Among the genes with transcripts returning to normal levels, ribosome assembly/biogenesis was most significant whereas in absence of DNMT1, a new set of 903 genes became dysregulated and are involved in similar pathways as mentioned above. These findings provide support for overexpression of DNMT1 as well as its downregulation as risk factor for the four disorders and that its levels within a tight range are essential for normal neurodevelopment/mental health.
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Affiliation(s)
- Minali Singh
- Molecular Biology and Genetics Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad, India
| | - Sonal Saxena
- Centre for Human Disease Research, Birla Institute of Technology and Science, Pilani, Hyderabad, India
| | - Kommu Naga Mohan
- Molecular Biology and Genetics Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad, India
- Centre for Human Disease Research, Birla Institute of Technology and Science, Pilani, Hyderabad, India
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4
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Win PW, Singh SM, Castellani CA. Mitochondrial DNA Copy Number and Heteroplasmy in Monozygotic Twins Discordant for Schizophrenia. Twin Res Hum Genet 2023:1-10. [PMID: 37655526 DOI: 10.1017/thg.2023.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Schizophrenia (SZ) is a severe, complex, and common mental disorder with high heritability (80%), an adult age of onset, and high discordance (∼50%) in monozygotic twins (MZ). Extensive studies on familial and non-familial cases have implicated a number of segregating mutations and de novo changes in SZ that may include changes to the mitochondrial genome. Yet, no single universally causal variant has been identified, highlighting its extensive genetic heterogeneity. This report specifically focuses on the assessment of changes in the mitochondrial genome in a unique set of monozygotic twins discordant (MZD) for SZ using blood. Genomic DNA from six pairs of MZD twins and two sets of parents (N = 16) was hybridized to the Affymetrix Human SNP Array 6.0 to assess mitochondrial DNA copy number (mtDNA-CN). Whole genome sequencing (WGS) and quantitative polymerase chain reaction (qPCR) was performed for a subset of MZD pairs and their parents and was also used to derive mtDNA-CN estimates. The WGS data were further analyzed to generate heteroplasmy (HP) estimates. Our results show that mtDNA-CN estimates for within-pair and mother-child differences were smaller than comparisons involving unrelated individuals, as expected. MZD twins showed discordance in mtDNA-CN estimates and displayed concordance in directionality of differences for mtDNA-CN across all technologies. Further, qPCR performed better than Affymetrix in estimating mtDNA-CN based on relatedness. No reliable differences in HP were detected between MZD twins. The within-MZD differences in mtDNA-CN observed represent postzygotic somatic changes that may contribute to discordance of MZ twins for diseases, including SZ.
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Affiliation(s)
- Phyo W Win
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, Canada
| | - Shiva M Singh
- Department of Biology, Western University, London, Canada
| | - Christina A Castellani
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, Canada
- Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Canada
- McKusick-Nathans Institute, Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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5
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Hagenbeek FA, Hirzinger JS, Breunig S, Bruins S, Kuznetsov DV, Schut K, Odintsova VV, Boomsma DI. Maximizing the value of twin studies in health and behaviour. Nat Hum Behav 2023:10.1038/s41562-023-01609-6. [PMID: 37188734 DOI: 10.1038/s41562-023-01609-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 04/19/2023] [Indexed: 05/17/2023]
Abstract
In the classical twin design, researchers compare trait resemblance in cohorts of identical and non-identical twins to understand how genetic and environmental factors correlate with resemblance in behaviour and other phenotypes. The twin design is also a valuable tool for studying causality, intergenerational transmission, and gene-environment correlation and interaction. Here we review recent developments in twin studies, recent results from twin studies of new phenotypes and recent insights into twinning. We ask whether the results of existing twin studies are representative of the general population and of global diversity, and we conclude that stronger efforts to increase representativeness are needed. We provide an updated overview of twin concordance and discordance for major diseases and mental disorders, which conveys a crucial message: genetic influences are not as deterministic as many believe. This has important implications for public understanding of genetic risk prediction tools, as the accuracy of genetic predictions can never exceed identical twin concordance rates.
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Affiliation(s)
- Fiona A Hagenbeek
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
- Amsterdam Public Health Research Institute, Amsterdam, the Netherlands.
| | - Jana S Hirzinger
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Sophie Breunig
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Department of Psychology & Neuroscience, University of Colorado Boulder, Boulder, CO, USA
- Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, CO, USA
| | - Susanne Bruins
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, Amsterdam, the Netherlands
| | - Dmitry V Kuznetsov
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Faculty of Sociology, Bielefeld University, Bielefeld, Germany
| | - Kirsten Schut
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Nightingale Health Plc, Helsinki, Finland
| | - Veronika V Odintsova
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Amsterdam Reproduction & Development (AR&D) Research Institute, Amsterdam, the Netherlands
- Department of Psychiatry, University Medical Center of Groningen, University of Groningen, Groningen, the Netherlands
| | - Dorret I Boomsma
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
- Amsterdam Public Health Research Institute, Amsterdam, the Netherlands.
- Amsterdam Reproduction & Development (AR&D) Research Institute, Amsterdam, the Netherlands.
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Dixon TA, Muotri AR. Advancing preclinical models of psychiatric disorders with human brain organoid cultures. Mol Psychiatry 2023; 28:83-95. [PMID: 35948659 PMCID: PMC9812789 DOI: 10.1038/s41380-022-01708-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 01/11/2023]
Abstract
Psychiatric disorders are often distinguished from neurological disorders in that the former do not have characteristic lesions or findings from cerebrospinal fluid, electroencephalograms (EEGs), or brain imaging, and furthermore do not have commonly recognized convergent mechanisms. Psychiatric disorders commonly involve clinical diagnosis of phenotypic behavioral disturbances of mood and psychosis, often with a poorly understood contribution of environmental factors. As such, psychiatric disease has been challenging to model preclinically for mechanistic understanding and pharmaceutical development. This review compares commonly used animal paradigms of preclinical testing with evolving techniques of induced pluripotent cell culture with a focus on emerging three-dimensional models. Advances in complexity of 3D cultures, recapitulating electrical activity in utero, and disease modeling of psychosis, mood, and environmentally induced disorders are reviewed. Insights from these rapidly expanding technologies are discussed as they pertain to the utility of human organoid and other models in finding novel research directions, validating pharmaceutical action, and recapitulating human disease.
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Affiliation(s)
- Thomas Anthony Dixon
- grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California San Diego, La Jolla, CA 92093 USA
| | - Alysson R. Muotri
- grid.266100.30000 0001 2107 4242Department of Pediatrics and Department of Cellular & Molecular Medicine, University of California San Diego, School of Medicine, Center for Academic Research and Training in Anthropogeny (CARTA), Kavli Institute for Brain and Mind, Archealization Center (ArchC), La Jolla, CA 92037 USA
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7
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Katrinli S, Maihofer AX, Wani AH, Pfeiffer JR, Ketema E, Ratanatharathorn A, Baker DG, Boks MP, Geuze E, Kessler RC, Risbrough VB, Rutten BPF, Stein MB, Ursano RJ, Vermetten E, Logue MW, Nievergelt CM, Smith AK, Uddin M. Epigenome-wide meta-analysis of PTSD symptom severity in three military cohorts implicates DNA methylation changes in genes involved in immune system and oxidative stress. Mol Psychiatry 2022; 27:1720-1728. [PMID: 34992238 PMCID: PMC9106882 DOI: 10.1038/s41380-021-01398-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/13/2021] [Accepted: 11/23/2021] [Indexed: 11/08/2022]
Abstract
Epigenetic factors modify the effects of environmental factors on biological outcomes. Identification of epigenetic changes that associate with PTSD is therefore a crucial step in deciphering mechanisms of risk and resilience. In this study, our goal is to identify epigenetic signatures associated with PTSD symptom severity (PTSS) and changes in PTSS over time, using whole blood DNA methylation (DNAm) data (MethylationEPIC BeadChip) of military personnel prior to and following combat deployment. A total of 429 subjects (858 samples across 2 time points) from three male military cohorts were included in the analyses. We conducted two different meta-analyses to answer two different scientific questions: one to identify a DNAm profile of PTSS using a random effects model including both time points for each subject, and the other to identify a DNAm profile of change in PTSS conditioned on pre-deployment DNAm. Four CpGs near four genes (F2R, CNPY2, BAIAP2L1, and TBXAS1) and 88 differentially methylated regions (DMRs) were associated with PTSS. Change in PTSS after deployment was associated with 15 DMRs, of those 2 DMRs near OTUD5 and ELF4 were also associated with PTSS. Notably, three PTSS-associated CpGs near F2R, BAIAP2L1 and TBXAS1 also showed nominal evidence of association with change in PTSS. This study, which identifies PTSD-associated changes in genes involved in oxidative stress and immune system, provides novel evidence that epigenetic differences are associated with PTSS.
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Affiliation(s)
- Seyma Katrinli
- Department of Gynecology and Obstetrics, Emory University, Atlanta, GA, USA
| | - Adam X Maihofer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Agaz H Wani
- Genomics Program, College of Public Health, University of South Florida, Tampa, FL, USA
| | - John R Pfeiffer
- Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, Urbana, IL, USA
| | - Elizabeth Ketema
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | | | - Dewleen G Baker
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, CA, USA
| | - Marco P Boks
- Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Elbert Geuze
- Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
- Brain Research and Innovation Centre, Netherlands Ministry of Defence, Utrecht, The Netherlands
| | - Ronald C Kessler
- Department of Health Care Policy, Harvard Medical School, Boston, MA, USA
| | - Victoria B Risbrough
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, CA, USA
| | - Bart P F Rutten
- Department of Psychiatry and Neuropsychology, Maastricht University Medical Centre, School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Murray B Stein
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- School of Public Health, University of California San Diego, La Jolla, CA, USA
| | - Robert J Ursano
- Center for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD, USA
| | - Eric Vermetten
- Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Psychiatry, Leiden University Medical Center, ZA, Leiden, The Netherlands
- Research Center, Netherlands Defense Department, UT, AA Utrecht, The Netherlands
- Arq Psychotrauma Expert Group, XE, Diemen, The Netherlands
| | - Mark W Logue
- National Center for PTSD, Behavioral Science Division at VA Boston Healthcare System, Boston, MA, USA
- Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Caroline M Nievergelt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- Veterans Affairs Center of Excellence for Stress and Mental Health, San Diego, CA, USA
| | - Alicia K Smith
- Department of Gynecology and Obstetrics, Emory University, Atlanta, GA, USA
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - Monica Uddin
- Genomics Program, College of Public Health, University of South Florida, Tampa, FL, USA.
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Srivastava A, Dada O, Qian J, Al-Chalabi N, Fatemi AB, Gerretsen P, Graff A, De Luca V. Epigenetics of Schizophrenia. Psychiatry Res 2021; 305:114218. [PMID: 34638051 DOI: 10.1016/j.psychres.2021.114218] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/07/2021] [Accepted: 09/20/2021] [Indexed: 12/31/2022]
Abstract
Schizophrenia (SCZ) is a chronic psychotic disorder that contributes significantly to disability, affecting behavior, thought, and cognition. It has long been known that there is a heritable component to schizophrenia; studies in both the pre-genomic and post-genomic era, however, have failed to elucidate fully the genetic basis for this complex disease. Epigenetic processes - broadly, those which contribute to changes in gene expression without altering the genetic code itself - may help to understand better the mechanisms leading to development of SCZ. The objective of this review is to synthesize current knowledge of the epigenetic mechanisms involved in schizophrenia. Specifically, DNA methylation studies in both peripheral and post-mortem brain samples in SCZ are reviewed, as are epigenetic mechanisms including histone modification. The promising role of non-coding RNA including micro-RNA (miRNA) and its role as a potential diagnostic and therapeutic biomarker is outlined, as are epigenetic age acceleration and telomere shortening. Finally, we discuss limitations in current knowledge and propose future research directions.
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Affiliation(s)
| | | | | | | | | | | | - Ariel Graff
- Department of Psychiatry, University of Toronto
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Riley M. Critical review of the evidence base regarding theories conceptualising the aetiology of psychosis. ACTA ACUST UNITED AC 2021; 29:1030-1037. [PMID: 32972234 DOI: 10.12968/bjon.2020.29.17.1030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A critical review of literature related to the aetiology of psychosis was conducted with specific emphasis on genetics. It was found that, although many published articles were retrieved via database searches, the format of the information was disparate in presentation leading to unnecessary inconsistences. This suggests the need for insightful collaboration by authors and standardisation of published articles to prevent academic and specialism barriers remaining as a discouragement to non-specialists wishing to access this information.
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Affiliation(s)
- Miv Riley
- Senior Care Co-ordinator, Early Intervention Service (Psychosis), Lancashire Care Foundation Trust and Manchester University
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10
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Hidden Role of Gut Microbiome Dysbiosis in Schizophrenia: Antipsychotics or Psychobiotics as Therapeutics? Int J Mol Sci 2021; 22:ijms22147671. [PMID: 34299291 PMCID: PMC8307070 DOI: 10.3390/ijms22147671] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia is a chronic, heterogeneous neurodevelopmental disorder that has complex symptoms and uncertain etiology. Mounting evidence indicates the involvement of genetics and epigenetic disturbances, alteration in gut microbiome, immune system abnormalities, and environmental influence in the disease, but a single root cause and mechanism involved has yet to be conclusively determined. Consequently, the identification of diagnostic markers and the development of psychotic drugs for the treatment of schizophrenia faces a high failure rate. This article surveys the etiology of schizophrenia with a particular focus on gut microbiota regulation and the microbial signaling system that correlates with the brain through the vagus nerve, enteric nervous system, immune system, and production of postbiotics. Gut microbially produced molecules may lay the groundwork for further investigations into the role of gut microbiota dysbiosis and the pathophysiology of schizophrenia. Current treatment of schizophrenia is limited to psychotherapy and antipsychotic drugs that have significant side effects. Therefore, alternative therapeutic options merit exploration. The use of psychobiotics alone or in combination with antipsychotics may promote the development of novel therapeutic strategies. In view of the individual gut microbiome structure and personalized response to antipsychotic drugs, a tailored and targeted manipulation of gut microbial diversity naturally by novel prebiotics (non-digestible fiber) may be a successful alternative therapeutic for the treatment of schizophrenia patients.
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11
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Munawar N, Ahsan K, Muhammad K, Ahmad A, Anwar MA, Shah I, Al Ameri AK, Al Mughairbi F. Hidden Role of Gut Microbiome Dysbiosis in Schizophrenia: Antipsychotics or Psychobiotics as Therapeutics? Int J Mol Sci 2021. [DOI: https://doi.org/10.3390/ijms22147671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Schizophrenia is a chronic, heterogeneous neurodevelopmental disorder that has complex symptoms and uncertain etiology. Mounting evidence indicates the involvement of genetics and epigenetic disturbances, alteration in gut microbiome, immune system abnormalities, and environmental influence in the disease, but a single root cause and mechanism involved has yet to be conclusively determined. Consequently, the identification of diagnostic markers and the development of psychotic drugs for the treatment of schizophrenia faces a high failure rate. This article surveys the etiology of schizophrenia with a particular focus on gut microbiota regulation and the microbial signaling system that correlates with the brain through the vagus nerve, enteric nervous system, immune system, and production of postbiotics. Gut microbially produced molecules may lay the groundwork for further investigations into the role of gut microbiota dysbiosis and the pathophysiology of schizophrenia. Current treatment of schizophrenia is limited to psychotherapy and antipsychotic drugs that have significant side effects. Therefore, alternative therapeutic options merit exploration. The use of psychobiotics alone or in combination with antipsychotics may promote the development of novel therapeutic strategies. In view of the individual gut microbiome structure and personalized response to antipsychotic drugs, a tailored and targeted manipulation of gut microbial diversity naturally by novel prebiotics (non-digestible fiber) may be a successful alternative therapeutic for the treatment of schizophrenia patients.
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12
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St Clair D, Lang B. Schizophrenia: a classic battle ground of nature versus nurture debate. Sci Bull (Beijing) 2021; 66:1037-1046. [PMID: 36654248 DOI: 10.1016/j.scib.2021.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/29/2020] [Accepted: 10/13/2020] [Indexed: 01/20/2023]
Abstract
Much has been learned about the etiology and pathogenesis of schizophrenia since the term was first used by Eugene Bleuler over a century ago to describe one of the most important forms of major mental illness to affect mankind. Both nature and nurture feature prominently in our understanding of the genesis of the overall risk of developing schizophrenia. We now have a firm grasp of the broad structure of the genetic architecture and several key environmental risk factors have been identified and delineated. However, much of the heritability of schizophrenia remains unexplained and the reported environmental risk factors do not explain all the variances not attributable to genetic risk factors. The biggest problem at present is that our understanding of the causal mechanisms involved is still in its infancy. In this review, we describe the extent and limits of our knowledge of the specific genetic/constitutional and non-genetic/environmental factors that contribute to the overall risk of schizophrenia. We suggest novel methods may be required to understand the almost certainly immensely complex multi-level causal mechanisms that contribute to the generation of the schizophrenia phenotype.
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Affiliation(s)
- David St Clair
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, National Clinical Research Center for Mental Disorders, Changsha 410011, China; Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK; Bio-X Life Science Research Center, Shanghai Jiao Tong University, Shanghai 200030, China.
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, National Clinical Research Center for Mental Disorders, Changsha 410011, China; Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK.
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13
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Singh RS, Singh KK, Singh SM. Origin of Sex-Biased Mental Disorders: An Evolutionary Perspective. J Mol Evol 2021; 89:195-213. [PMID: 33630117 PMCID: PMC8116267 DOI: 10.1007/s00239-021-09999-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/06/2021] [Indexed: 12/12/2022]
Abstract
Sexual dimorphism or sex bias in diseases and mental disorders have two biological causes: sexual selection and sex hormones. We review the role of sexual selection theory and bring together decades of molecular studies on the variation and evolution of sex-biased genes and provide a theoretical basis for the causes of sex bias in disease and health. We present a Sexual Selection-Sex Hormone theory and show that male-driven evolution, including sexual selection, leads to: (1) increased male vulnerability due to negative pleiotropic effects associated with male-driven sexual selection and evolution; (2) increased rates of male-driven mutations and epimutations in response to early fitness gains and at the cost of late fitness; and (3) enhanced female immunity due to antagonistic responses to mutations that are beneficial to males but harmful to females, reducing female vulnerability to diseases and increasing the thresholds for disorders such as autism. Female-driven evolution, such as reproduction-related fluctuation in female sex hormones in association with stress and social condition, has been shown to be associated with increased risk of certain mental disorders such as major depression disorder in women. Bodies have history, cells have memories. An evolutionary framework, such as the Sexual Selection–Sex Hormone theory, provides a historical perspective for understanding how the differences in the sex-biased diseases and mental disorders have evolved over time. It has the potential to direct the development of novel preventive and treatment strategies.
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Affiliation(s)
- Rama S Singh
- Department of Biology, McMaster University, Hamilton, Canada.
| | - Karun K Singh
- Stem Cell and Cancer Research Institute, McMaster University, Hamilton, Canada.,Krembil Research Institute, University Health Network, Toronto, Canada
| | - Shiva M Singh
- Department of Biology, University of Western Ontario, London, Canada
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14
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Richetto J, Meyer U. Epigenetic Modifications in Schizophrenia and Related Disorders: Molecular Scars of Environmental Exposures and Source of Phenotypic Variability. Biol Psychiatry 2021; 89:215-226. [PMID: 32381277 DOI: 10.1016/j.biopsych.2020.03.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/19/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
Epigenetic modifications are increasingly recognized to play a role in the etiology and pathophysiology of schizophrenia and other psychiatric disorders with developmental origins. Here, we summarize clinical and preclinical findings of epigenetic alterations in schizophrenia and relevant disease models and discuss their putative origin. Recent findings suggest that certain schizophrenia risk loci can influence stochastic variation in gene expression through epigenetic processes, highlighting the intricate interaction between genetic and epigenetic control of neurodevelopmental trajectories. In addition, a substantial portion of epigenetic alterations in schizophrenia and related disorders may be acquired through environmental factors and may be manifested as molecular "scars." Some of these scars can influence brain functions throughout the entire lifespan and may even be transmitted across generations via epigenetic germline inheritance. Epigenetic modifications, whether caused by genetic or environmental factors, are plausible molecular sources of phenotypic heterogeneity and offer a target for therapeutic interventions. The further elucidation of epigenetic modifications thus may increase our knowledge regarding schizophrenia's heterogeneous etiology and pathophysiology and, in the long term, may advance personalized treatments through the use of biomarker-guided epigenetic interventions.
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Affiliation(s)
- Juliet Richetto
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, and Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
| | - Urs Meyer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, and Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
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15
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Mohammadnejad A, Soerensen M, Baumbach J, Mengel‐From J, Li W, Lund J, Li S, Christiansen L, Christensen K, Hjelmborg JVB, Tan Q. Novel DNA methylation marker discovery by assumption-free genome-wide association analysis of cognitive function in twins. Aging Cell 2021; 20:e13293. [PMID: 33528912 PMCID: PMC7884045 DOI: 10.1111/acel.13293] [Citation(s) in RCA: 6] [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: 06/08/2020] [Revised: 11/23/2020] [Accepted: 12/01/2020] [Indexed: 01/23/2023] Open
Abstract
Privileged by rapid increase in available epigenomic data, epigenome-wide association studies (EWAS) are to make a profound contribution to understand the molecular mechanism of DNA methylation in cognitive aging. Current statistical methods used in EWAS are dominated by models based on multiple assumptions, for example, linear relationship between molecular profiles and phenotype, normal distribution for the methylation data and phenotype. In this study, we applied an assumption-free method, the generalized correlation coefficient (GCC), and compare it to linear models, namely the linear mixed model and kinship model. We use DNA methylation associated with a cognitive score in 400 and 206 twins as discovery and replication samples respectively. DNA methylation associated with cognitive function using GCC, linear mixed model, and kinship model, identified 65 CpGs (p < 1e-04) from discovery sample displaying both nonlinear and linear correlations. Replication analysis successfully replicated 9 of these top CpGs. When combining results of GCC and linear models to cover diverse patterns of relationships, we identified genes like KLHDC4, PAPSS2, and MRPS18B as well as pathways including focal adhesion, axon guidance, and some neurological signaling. Genomic region-based analysis found 15 methylated regions harboring 11 genes, with three verified in gene expression analysis, also the 11 genes were related to top functional clusters including neurohypophyseal hormone and maternal aggressive behaviors. The GCC approach detects valuable methylation sites missed by traditional linear models. A combination of methylation markers from GCC and linear models enriched biological pathways sensible in neurological function that could implicate cognitive performance and cognitive aging.
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Affiliation(s)
- Afsaneh Mohammadnejad
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
| | - Mette Soerensen
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Unit of Human GeneticsDepartment of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
- Department of Clinical Biochemistry and PharmacologyOdense University HospitalOdenseDenmark
| | - Jan Baumbach
- Computational BiomedicineDepartment of Mathematics and Computer ScienceUniversity of Southern DenmarkOdenseDenmark
- Chair of Experimental BioinformaticsTUM School of Life SciencesTechnical University of MunichMunichGermany
| | - Jonas Mengel‐From
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Unit of Human GeneticsDepartment of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Weilong Li
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Population Research UnitFaculty of Social SciencesUniversity of HelsinkiHelsinkiFinland
| | - Jesper Lund
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Digital Health & Machine Learning Research GroupHasso Plattner Institute for Digital EngineeringPotsdamGermany
| | - Shuxia Li
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
| | - Lene Christiansen
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Department of Clinical ImmunologyCopenhagen University HospitalRigshospitaletCopenhagen ØDenmark
| | - Kaare Christensen
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Unit of Human GeneticsDepartment of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Jacob V. B. Hjelmborg
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
| | - Qihua Tan
- Unit of Epidemiology, Biostatistics and BiodemographyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
- Unit of Human GeneticsDepartment of Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
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16
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Di Bartolomeo M, Stark T, Maurel OM, Iannotti FA, Kuchar M, Ruda-Kucerova J, Piscitelli F, Laudani S, Pekarik V, Salomone S, Arosio B, Mechoulam R, Maccarrone M, Drago F, Wotjak CT, Di Marzo V, Vismara M, Dell'Osso B, D'Addario C, Micale V. Crosstalk between the transcriptional regulation of dopamine D2 and cannabinoid CB1 receptors in schizophrenia: Analyses in patients and in perinatal Δ9-tetrahydrocannabinol-exposed rats. Pharmacol Res 2021; 164:105357. [PMID: 33285233 DOI: 10.1016/j.phrs.2020.105357] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/07/2020] [Accepted: 11/28/2020] [Indexed: 02/08/2023]
Abstract
Perinatal exposure to Δ9-tetrahydrocannabinol (THC) affects brain development and might increase the incidence of psychopathology later in life, which seems to be related to a dysregulation of endocannabinoid and/or dopaminergic systems. We here evaluated the transcriptional regulation of the genes encoding for the cannabinoid CB1 receptor (Cnr1) and the dopamine D2 receptor (Drd2) in perinatal THC-(pTHC) exposed male rats, focusing on the role of DNA methylation analyzed by pyrosequencing. Simultaneously, the molecular and behavioral abnormalities at two different time points (i.e., neonatal age and adulthood) and the potential preventive effect of peripubertal treatment with cannabidiol, a non-euphoric component of Cannabis, were assessed. The DRD2 methylation was also evaluated in a cohort of subjects with schizophrenia. We observed an increase in both Cnr1 and Drd2 mRNA levels selectively in the prefrontal cortex of adult pTHC-exposed rats with a consistent reduction in DNA methylation at the Drd2 regulatory region, paralleled by social withdrawal and cognitive impairment which were reversed by cannabidiol treatment. These adult abnormalities were preceded at neonatal age by delayed appearance of neonatal reflexes, higher Drd2 mRNA and lower 2-arachidonoylglycerol (2-AG) brain levels, which persisted till adulthood. Alterations of the epigenetic mark for DRD2 were also found in subjects with schizophrenia. Overall, reported data add further evidence to the dopamine-cannabinoid interaction in terms of DRD2 and CNR1 dysregulation which could be implicated in the pathogenesis of schizophrenia spectrum disorders, suggesting that cannabidiol treatment may normalize pTHC-induced psychopathology by modulating the altered dopaminergic activity.
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Affiliation(s)
- Martina Di Bartolomeo
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Tibor Stark
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic; Neuronal Plasticity Research Group, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Oriana Maria Maurel
- Neuronal Plasticity Research Group, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - Fabio Arturo Iannotti
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy
| | - Martin Kuchar
- Forensic Laboratory of Biologically Active Substances, Department of Chemistry of Natural Compounds, University of Chemistry and Technology Prague, Prague, Czech Republic; National Institute of Mental Health, Klecany, Czech Republic
| | - Jana Ruda-Kucerova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Fabiana Piscitelli
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy
| | - Samuele Laudani
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - Vladimir Pekarik
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Salvatore Salomone
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - Beatrice Arosio
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy; Fondazione Ca' Granda, IRCCS, Ospedale Maggiore Policlinico, Milan, Italy
| | - Raphael Mechoulam
- Institute for Drug Research, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mauro Maccarrone
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy; European Center for Brain Research, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - Carsten T Wotjak
- Neuronal Plasticity Research Group, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; Boehringer Ingelheim Pharma GmbH & KO KG, Germany
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy; Canada Excellence Research Chair on the Microbiome-Endocannabinoidome Axis in Metabolic, Health, Université Laval, Quebec City, Canada; Joint International Unit on Chemical and Biomolecular Research on the Microbiome and its Impact on Metabolic Health and Nutrition (UMI-MicroMeNu), between Université Laval and Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Matteo Vismara
- Department of Biomedical and Clinical Sciences 'Luigi Sacco', University of Milan, Milan, Italy; Department of Mental Health, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Bernardo Dell'Osso
- Department of Biomedical and Clinical Sciences 'Luigi Sacco', University of Milan, Milan, Italy; Department of Mental Health, ASST Fatebenefratelli-Sacco, Milan, Italy; "Aldo Ravelli" Research Center for Neurotechnology and Experimental Brain Therapeutics, Department of Health Sciences, University of Milan Medical School, Milan, Italy; Department of Psychiatry and Behavioral Sciences, Stanford University, California, USA
| | - Claudio D'Addario
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy; National Institute of Mental Health, Klecany, Czech Republic.
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17
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Carmel M, Michaelovsky E, Weinberger R, Frisch A, Mekori-Domachevsky E, Gothelf D, Weizman A. Differential methylation of imprinting genes and MHC locus in 22q11.2 deletion syndrome-related schizophrenia spectrum disorders. World J Biol Psychiatry 2021; 22:46-57. [PMID: 32212948 DOI: 10.1080/15622975.2020.1747113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVES 22q11.2 deletion syndrome (DS) is the strongest known genetic risk for schizophrenia. Methylome screening was conducted to elucidate possible involvement of epigenetic alterations in the emergence of schizophrenia spectrum disorders (SZ-SD) in 22q11.2DS. METHODS Sixteen adult men with/without SZ-SD were recruited from a 22q11.2DS cohort and underwent genome-wide DNA methylation profile analysis. Differentially methylated probes (DMPs) and regions (DMRs) were analysed using the ChAMP software. RESULTS The DMPs (p-value <10-6) and DMRs (p-valueArea <0.01) were enriched in two gene sets, 'imprinting genes' and 'chr6p21', a region overlapping the MHC locus. Most of the identified imprinting genes are involved in neurodevelopment and located in clusters under imprinting control region (ICR) regulation, including PEG10, SGCE (7q21.3), GNAS, GNAS-AS1 (20q13.32) and SNHG14, SNURF-SNRPN, SNORD115 (15q11.2). The differentially methylated genes from the MHC locus included immune HLA-genes and non-immune genes, RNF39, PPP1R18 and NOTCH4, implicated in neurodevelopment and synaptic plasticity. The most significant DMR is located in MHC locus and covered the transcription regulator ZFP57 that is required for control and maintenance of gene imprinting at multiple ICRs. CONCLUSIONS The differential methylation in imprinting genes and in chr6p21-22 indicate the neurodevelopmental nature of 22q11.2DS-related SZ and the major role of MHC locus in the risk to develop SZ.
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Affiliation(s)
- Miri Carmel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Elena Michaelovsky
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Ronnie Weinberger
- The Behavioral Neurogenetics Center and Child Psychiatry Division, Sheba Medical Center, Ramat Gan, Israel
| | - Amos Frisch
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Ehud Mekori-Domachevsky
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Behavioral Neurogenetics Center and Child Psychiatry Division, Sheba Medical Center, Ramat Gan, Israel
| | - Doron Gothelf
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Behavioral Neurogenetics Center and Child Psychiatry Division, Sheba Medical Center, Ramat Gan, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Petach Tikva, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Geha Mental Health Center, Petach Tikva, Israel
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18
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Imamura A, Morimoto Y, Ono S, Kurotaki N, Kanegae S, Yamamoto N, Kinoshita H, Tsujita T, Okazaki Y, Ozawa H. Genetic and environmental factors of schizophrenia and autism spectrum disorder: insights from twin studies. J Neural Transm (Vienna) 2020; 127:1501-1515. [PMID: 32285255 PMCID: PMC7578126 DOI: 10.1007/s00702-020-02188-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/05/2020] [Indexed: 02/06/2023]
Abstract
Twin studies of psychiatric disorders such as schizophrenia and autism spectrum disorder have employed epidemiological approaches that determine heritability by comparing the concordance rate between monozygotic twins (MZs) and dizygotic twins. The basis for these studies is that MZs share 100% of their genetic information. Recently, biological studies based on molecular methods are now being increasingly applied to examine the differences between MZs discordance for psychiatric disorders to unravel their possible causes. Although recent advances in next-generation sequencing have increased the accuracy of this line of research, there has been greater emphasis placed on epigenetic changes versus DNA sequence changes as the probable cause of discordant psychiatric disorders in MZs. Since the epigenetic status differs in each tissue type, in addition to the DNA from the peripheral blood, studies using DNA from nerve cells induced from postmortem brains or induced pluripotent stem cells are being carried out. Although it was originally thought that epigenetic changes occurred as a result of environmental factors, and thus were not transmittable, it is now known that such changes might possibly be transmitted between generations. Therefore, the potential possible effects of intestinal flora inside the body are currently being investigated as a cause of discordance in MZs. As a result, twin studies of psychiatric disorders are greatly contributing to the elucidation of genetic and environmental factors in the etiology of psychiatric conditions.
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Affiliation(s)
- Akira Imamura
- Child and Adolescent Psychiatry Community Partnership Unit, Nagasaki University Hospital, Nagasaki, Japan.
| | - Yoshiro Morimoto
- Unit of Translation Medicine, Department of Neuropsychiatry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Shinji Ono
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Naohiro Kurotaki
- Department of Clinical Psychiatry, Graduate School of Medicine, Kagawa University, Kita-gun, Japan
| | - Shinji Kanegae
- Child and Adolescent Psychiatry Community Partnership Unit, Nagasaki University Hospital, Nagasaki, Japan
| | - Naoki Yamamoto
- Child and Adolescent Psychiatry Community Partnership Unit, Nagasaki University Hospital, Nagasaki, Japan
- Unit of Translation Medicine, Department of Neuropsychiatry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hirohisa Kinoshita
- Unit of Translation Medicine, Department of Neuropsychiatry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | | | - Yuji Okazaki
- Koseikai Michinoo Hospital, Nagasaki, Japan
- Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan
| | - Hiroki Ozawa
- Child and Adolescent Psychiatry Community Partnership Unit, Nagasaki University Hospital, Nagasaki, Japan
- Unit of Translation Medicine, Department of Neuropsychiatry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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19
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Yoshino Y, Dwivedi Y. Non-Coding RNAs in Psychiatric Disorders and Suicidal Behavior. Front Psychiatry 2020; 11:543893. [PMID: 33101077 PMCID: PMC7522197 DOI: 10.3389/fpsyt.2020.543893] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/14/2020] [Indexed: 12/18/2022] Open
Abstract
It is well known that only a small proportion of the human genome code for proteins; the rest belong to the family of RNAs that do not code for protein and are known as non-coding RNAs (ncRNAs). ncRNAs are further divided into two subclasses based on size: 1) long non-coding RNAs (lncRNAs; >200 nucleotides) and 2) small RNAs (<200 nucleotides). Small RNAs contain various family members that include microRNAs (miRNAs), small interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and small nuclear RNAs (snRNAs). The roles of ncRNAs, especially lncRNAs and miRNAs, are well documented in brain development, homeostasis, stress responses, and neural plasticity. It has also been reported that ncRNAs can influence the development of psychiatric disorders including schizophrenia, major depressive disorder, and bipolar disorder. More recently, their roles are being investigated in suicidal behavior. In this article, we have comprehensively reviewed the findings of lncRNA and miRNA expression changes and their functions in various psychiatric disorders including suicidal behavior. We primarily focused on studies that have been done in postmortem human brain. In addition, we have briefly reviewed the role of other small RNAs (e.g. piwiRNA, siRNA, snRNA, and snoRNAs) and their expression changes in psychiatric illnesses.
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Affiliation(s)
- Yuta Yoshino
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Yogesh Dwivedi
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
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20
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Twin studies of brain structure and cognition in schizophrenia. Neurosci Biobehav Rev 2019; 109:103-113. [PMID: 31843545 DOI: 10.1016/j.neubiorev.2019.12.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 11/20/2022]
Abstract
Twin studies in schizophrenia have been crucial in establishing estimates for the heritability and thus providing evidence for a genetic component in this disorder. Recent years have seen the application of the twin study paradigm to both putative intermediate phenotypes and biomarkers of disease as well as a diversification of its use in schizophrenia research. This review addressed studies of brain structure (T1 morphometry) and cognition in schizophrenia using twin study designs. We review major findings such as the overlap of genetic variance between schizophrenia and cognition as a model for the emergence of psychopathology. The use of novel hybrid models integrating molecular genetic risk markers, as well as the use of twin studies in epigenetics might prove to significantly enhance schizophrenia research in the post-GWAS era.
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21
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Saffari A, Arno M, Nasser E, Ronald A, Wong CCY, Schalkwyk LC, Mill J, Dudbridge F, Meaburn EL. RNA sequencing of identical twins discordant for autism reveals blood-based signatures implicating immune and transcriptional dysregulation. Mol Autism 2019; 10:38. [PMID: 31719968 PMCID: PMC6839145 DOI: 10.1186/s13229-019-0285-1] [Citation(s) in RCA: 10] [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: 04/26/2019] [Accepted: 09/01/2019] [Indexed: 11/13/2022] Open
Abstract
Background A gap exists in our mechanistic understanding of how genetic and environmental risk factors converge at the molecular level to result in the emergence of autism symptoms. We compared blood-based gene expression signatures in identical twins concordant and discordant for autism spectrum condition (ASC) to differentiate genetic and environmentally driven transcription differences, and establish convergent evidence for biological mechanisms involved in ASC. Methods Genome-wide gene expression data were generated using RNA-seq on whole blood samples taken from 16 pairs of monozygotic (MZ) twins and seven twin pair members (39 individuals in total), who had been assessed for ASC and autism traits at age 12. Differential expression (DE) analyses were performed between (a) affected and unaffected subjects (N = 36) and (b) within discordant ASC MZ twin pairs (total N = 11) to identify environmental-driven DE. Gene set enrichment and pathway testing was performed on DE gene lists. Finally, an integrative analysis using DNA methylation data aimed to identify genes with consistent evidence for altered regulation in cis. Results In the discordant twin analysis, three genes showed evidence for DE at FDR < 10%: IGHG4, EVI2A and SNORD15B. In the case-control analysis, four DE genes were identified at FDR < 10% including IGHG4, PRR13P5, DEPDC1B, and ZNF501. We find enrichment for DE of genes curated in the SFARI human gene database. Pathways showing evidence of enrichment included those related to immune cell signalling and immune response, transcriptional control and cell cycle/proliferation. Integrative methylomic and transcriptomic analysis identified a number of genes showing suggestive evidence for cis dysregulation. Limitations Identical twins stably discordant for ASC are rare, and as such the sample size was limited and constrained to the use of peripheral blood tissue for transcriptomic and methylomic profiling. Given these primary limitations, we focused on transcript-level analysis. Conclusions Using a cohort of ASC discordant and concordant MZ twins, we add to the growing body of transcriptomic-based evidence for an immune-based component in the molecular aetiology of ASC. Whilst the sample size was limited, the study demonstrates the utility of the discordant MZ twin design combined with multi-omics integration for maximising the potential to identify disease-associated molecular signals.
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Affiliation(s)
- Ayden Saffari
- 1Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- 2Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck, University of London, London, UK
| | - Matt Arno
- 3Edinburgh Genomics, University of Edinburgh, Edinburgh, Scotland UK
- 4King's Genomics Centre, King's College London, London, UK
| | - Eric Nasser
- 4King's Genomics Centre, King's College London, London, UK
| | - Angelica Ronald
- 2Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck, University of London, London, UK
| | - Chloe C Y Wong
- 5Social Genetic and Developmental Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | - Jonathan Mill
- 7University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Frank Dudbridge
- 1Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- 8Department of Health Sciences, University of Leicester, Leicester, UK
| | - Emma L Meaburn
- 2Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck, University of London, London, UK
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22
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Chellappa SA, Pathak AK, Sinha P, Jainarayanan ASHWINK, Jain S, Brahmachari SK. Meta-analysis of genomic variants and gene expression data in schizophrenia suggests the potential need for adjunctive therapeutic interventions for neuropsychiatric disorders. J Genet 2019. [DOI: 10.1007/s12041-019-1101-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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23
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Anirudh Chellappa S, Pathak AK, Sinha P, Jainarayanan AK, Jain S, Brahmachari SK. Meta-analysis of genomic variants and gene expression data in schizophrenia suggests the potential need for adjunctive therapeutic interventions for neuropsychiatric disorders. J Genet 2019; 98:60. [PMID: 31204709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Schizophrenia (SZ) is a debilitating mental illness with a multigenic aetiology and significant heritability. Despite extensive genetic studies, the molecular aetiology has remained enigmatic. A recent systems biology study suggested a protein-protein interaction network for SZ with 504 novel interactions. The onset of psychiatric disorders is predominant during adolescence, often accompanied by subtle structural abnormalities in multiple regions of the brain. The availability of BrainSpan Atlas data allowed us to re-examine the genes present in the SZ interactome as a function of space and time. The availability of genomes of healthy centenarians and nonpsychiatric Exome Aggregation Consortium database allowed us to identify the variants of criticality. The expression of the SZ candidate genes responsible for cognition and disease onset was studied in different brain regions during particular developmental stages. A subset of novel interactors detected in the network was further validated using gene expression data of post-mortem brains of patients with psychiatric illness. We have narrowed down the list of drug targets proposed by theprevious interactome study to 10 proteins. These proteins belonging to 81 biological pathways are targeted by 34 known Food and Drug Administration-approved drugs that have distinct potential for the treatment of neuropsychiatric disorders. We also report the possibility of targeting key genes belonging to celecoxib pharmacodynamics, Gα signalling and cGMP-PKG signalling pathwaysthat are not known to be specific to SZ aetiology.
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Affiliation(s)
- S Anirudh Chellappa
- Centre for Open Innovation - Indian Centre for Social Transformation (ICST), Bengaluru 560 001, India
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Griñán-Ferré C, Corpas R, Puigoriol-Illamola D, Palomera-Ávalos V, Sanfeliu C, Pallàs M. Understanding Epigenetics in the Neurodegeneration of Alzheimer's Disease: SAMP8 Mouse Model. J Alzheimers Dis 2019; 62:943-963. [PMID: 29562529 PMCID: PMC5870033 DOI: 10.3233/jad-170664] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epigenetics is emerging as the missing link among genetic inheritance, environmental influences, and body and brain health status. In the brain, specific changes in nucleic acids or their associated proteins in neurons and glial cells might imprint differential patterns of gene activation that will favor either cognitive enhancement or cognitive loss for more than one generation. Furthermore, derangement of age-related epigenetic signaling is appearing as a significant risk factor for illnesses of aging, including neurodegeneration and Alzheimer’s disease (AD). In addition, better knowledge of epigenetic mechanisms might provide hints and clues in the triggering and progression of AD. Intense research in experimental models suggests that molecular interventions for modulating epigenetic mechanisms might have therapeutic applications to promote cognitive maintenance through an advanced age. The SAMP8 mouse is a senescence model with AD traits in which the study of epigenetic alterations may unveil epigenetic therapies against the AD.
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Affiliation(s)
- Christian Griñán-Ferré
- Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section) and Institute of Neuroscience, University of Barcelona and CIBERNED, Barcelona, Spain
| | - Rubén Corpas
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC, IDIBAPS and CIBERESP, Barcelona, Spain
| | - Dolors Puigoriol-Illamola
- Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section) and Institute of Neuroscience, University of Barcelona and CIBERNED, Barcelona, Spain
| | - Verónica Palomera-Ávalos
- Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section) and Institute of Neuroscience, University of Barcelona and CIBERNED, Barcelona, Spain
| | - Coral Sanfeliu
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC, IDIBAPS and CIBERESP, Barcelona, Spain
| | - Mercè Pallàs
- Department of Pharmacology, Toxicology and Therapeutic Chemistry (Pharmacology Section) and Institute of Neuroscience, University of Barcelona and CIBERNED, Barcelona, Spain
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25
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Gibbons A, Udawela M, Dean B. Non-Coding RNA as Novel Players in the Pathophysiology of Schizophrenia. Noncoding RNA 2018; 4:E11. [PMID: 29657307 PMCID: PMC6027250 DOI: 10.3390/ncrna4020011] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 03/29/2018] [Accepted: 04/06/2018] [Indexed: 12/22/2022] Open
Abstract
Schizophrenia is associated with diverse changes in the brain's transcriptome and proteome. Underlying these changes is the complex dysregulation of gene expression and protein production that varies both spatially across brain regions and temporally with the progression of the illness. The growing body of literature showing changes in non-coding RNA in individuals with schizophrenia offers new insights into the mechanisms causing this dysregulation. A large number of studies have reported that the expression of microRNA (miRNA) is altered in the brains of individuals with schizophrenia. This evidence is complemented by findings that single nucleotide polymorphisms (SNPs) in miRNA host gene sequences can confer an increased risk of developing the disorder. Additionally, recent evidence suggests the expression of other non-coding RNAs, such as small nucleolar RNA and long non-coding RNA, may also be affected in schizophrenia. Understanding how these changes in non-coding RNAs contribute to the development and progression of schizophrenia offers potential avenues for the better treatment and diagnosis of the disorder. This review will focus on the evidence supporting the involvement of non-coding RNA in schizophrenia and its therapeutic potential.
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Affiliation(s)
- Andrew Gibbons
- The Florey Institute for Neuroscience and Mental Health, 30 Royal Parade, Parkville, VIC 3052, Australia.
- The Department of Psychiatry, the University of Melbourne, Parkville, Victoria, Australia.
| | - Madhara Udawela
- The Florey Institute for Neuroscience and Mental Health, 30 Royal Parade, Parkville, VIC 3052, Australia.
| | - Brian Dean
- The Florey Institute for Neuroscience and Mental Health, 30 Royal Parade, Parkville, VIC 3052, Australia.
- The Centre for Mental Health, Swinburne University of Technology, Hawthorn, Victoria, Australia.
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26
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Liu C, Jiao C, Wang K, Yuan N. DNA Methylation and Psychiatric Disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 157:175-232. [PMID: 29933950 DOI: 10.1016/bs.pmbts.2018.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
DNA methylation has been an important area of research in the study of molecular mechanism to psychiatric disorders. Recent evidence has suggested that abnormalities in global methylation, methylation of genes, and pathways could play a role in the etiology of many forms of mental illness. In this article, we review the mechanisms of DNA methylation, including the genetic and environmental factors affecting methylation changes. We report and discuss major findings regarding DNA methylation in psychiatric patients, both within the context of global methylation studies and gene-specific methylation studies. Finally, we discuss issues surrounding data quality improvement, the limitations of current methylation analysis methods, and the possibility of using DNA methylation-based treatment for psychiatric disorders in the future.
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Affiliation(s)
- Chunyu Liu
- University of Illinois, Chicago, IL, United States; School of Life Science, Central South University, Changsha, China.
| | - Chuan Jiao
- School of Life Science, Central South University, Changsha, China
| | - Kangli Wang
- School of Life Science, Central South University, Changsha, China
| | - Ning Yuan
- Hunan Brain Hospital, Changsha, China
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Scarr E, Udawela M, Dean B. Changed frontal pole gene expression suggest altered interplay between neurotransmitter, developmental, and inflammatory pathways in schizophrenia. NPJ SCHIZOPHRENIA 2018; 4:4. [PMID: 29463818 PMCID: PMC5820249 DOI: 10.1038/s41537-018-0044-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 12/22/2022]
Abstract
Schizophrenia (Sz) probably occurs after genetically susceptible individuals encounter a deleterious environmental factor that triggers epigenetic mechanisms to change CNS gene expression. To determine if omnibus changes in CNS gene expression are present in Sz, we compared mRNA levels in the frontal pole (Brodmann’s area (BA) 10), the dorsolateral prefrontal cortex (BA 9) and cingulate cortex (BA 33) from 15 subjects with Sz and 15 controls using the Affymetrix™ Human Exon 1.0 ST Array. Differences in mRNA levels (±≥20%; p < 0.01) were identified (JMP Genomics 5.1) and used to predict pathways and gene x gene interactions that would be affected by the changes in gene expression using Ingenuity Pathway Analysis. There was significant variation in mRNA levels with diagnoses for 566 genes in BA 10, 65 genes in BA 9 and 40 genes in BA 33. In Sz, there was an over-representation of genes with changed expression involved in inflammation and development in BA 10, cell morphology in BA 9 and amino acid metabolism and small molecule biochemistry in BA 33. Using 94 genes with altered levels of expression in BA 10 from subjects with Sz, it was possible to construct an interactome of proven direct gene x gene interactions that was enriched for genes in inflammatory, developmental, oestrogen, serotonergic, cholinergic and NRG1 regulated pathways. Our data shows complex, regionally specific changes in cortical gene expression in Sz that are predicted to affect homeostasis between biochemical pathways already proposed to be important in the pathophysiology of the disorder. Anterior brain regions exhibit significant amounts of differentially-expressed genes which might cause dysfunction in schizophrenia. It’s thought that schizophrenia occurs when environmental factors trigger gene expression changes and downstream effects in the human brain, though this is not fully understood. An Australian research group led by Brian Dean, from the Florey Institute of Neuroscience and Mental Health, conducted a post-mortem human brain study in which they compared gene expression between 15 schizophrenia patients and 15 controls. They found 566 instances of altered gene expression in the most frontal part of the brain, Brodmann Area 10, and fewer changes in proximal regions. These are brain areas known to mediate schizophrenia-related traits and the changes in gene expression in these areas will affect a range of essential biological pathways. The group also found 97 differentially-expressed genes that have been shown to directly interact with each. This study paints a complex picture of the causes of schizophrenia but suggests modern technologies can help unravel these complexities.
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Affiliation(s)
- Elizabeth Scarr
- Molecular Psychiatry Laboratory, Florey Institute for Neuroscience and Mental Health, Parkville, VIC 3052, Australia.,CRC for Mental Health, Carlton, VIC, 3053, Australia.,Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Madhara Udawela
- Molecular Psychiatry Laboratory, Florey Institute for Neuroscience and Mental Health, Parkville, VIC 3052, Australia.,CRC for Mental Health, Carlton, VIC, 3053, Australia
| | - Brian Dean
- Molecular Psychiatry Laboratory, Florey Institute for Neuroscience and Mental Health, Parkville, VIC 3052, Australia. .,CRC for Mental Health, Carlton, VIC, 3053, Australia. .,Research Centre for Mental Health, the Faculty of Health, Arts and Design, Swinburne University, Hawthorne, VIC, 3122, Australia.
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28
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Bolund ACS, Starnawska A, Miller MR, Schlünssen V, Backer V, Børglum AD, Christensen K, Tan Q, Christiansen L, Sigsgaard T. Lung function discordance in monozygotic twins and associated differences in blood DNA methylation. Clin Epigenetics 2017; 9:132. [PMID: 29299071 PMCID: PMC5740718 DOI: 10.1186/s13148-017-0427-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/23/2017] [Indexed: 01/16/2023] Open
Abstract
Background Lung function is an important predictor of morbidity and mortality, with accelerated lung function decline reported to have immense consequences for the world's healthcare systems. The lung function decline across individual's lifetime is a consequence of age-related changes in lung anatomical structure and combination of various environmental factors; however, the exact molecular mechanisms contributing to this decline are not fully understood. DNA methylation is an epigenetic modification that changes across individual's lifetime, as well as allows for interplay between environmental and genetic factors. DNA methylation plays a crucial role in regulation of gene expression, with increasing evidence linking aberrant DNA methylation levels with a number of common human diseases. In this study, we investigated possible associations between genome-wide DNA methylation levels and lung function in 169 pairs of middle-aged monozygotic twins (86 male pairs: mean age (min-max) = 66 years (57-79); 83 female pairs: mean age (min-max) = 66 years (56-78)). The twins were collected from the Danish Twin Registry and were examined at baseline (1998-1999) and follow-up (2008-2011) visits. Using the twin design, we correlated intra-pair differences in cross-sectional and longitudinal lung function with intra-pair blood DNA methylation differences at follow-up by linear regression analyses adjusted for sex, age, BMI, smoking, and blood cell composition measured for each individual with the use of flow cytometry. Results We identified several differentially methylated CpG sites associated with forced expiratory volume the first second (FEV1) and forced vital capacity (FVC). Three probes identified for level of FVC were located in GLIPR1L2 gene (lowest p value = 7.14 × 10-8), involved in innate immunity and tumour-suppressor/pro-oncogenic mechanisms. Change in FEV1 during the 11-year follow-up period was associated with blood DNA methylation level in TRIM27 gene (p value = 1.55 × 10-6), a negative regulator of CD4 T cells, and also involved in cancer development. Several enriched pathways were identified, especially for FEV1, with one being "TGFBR" (Benjamini-Hochbergadjp value = 0.045), the receptor for TGFβ, a growth factor involved in normal lung tissue repair through pro-fibrotic effects. Conclusions Our findings suggest that epigenetic regulation of immunological- and cancer-related genes, as well as TGF-β-receptor-related genes, may be involved in the cross-sectional level and longitudinal change in lung function in middle-aged monozygotic twins.
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Affiliation(s)
- Anneli C. S. Bolund
- Department of Public Health, Section for Environment Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
| | - Anna Starnawska
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, 8000 Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Martin R. Miller
- Institute of Occupational and Environmental Medicine, University of Birmingham, Birmingham, UK
| | - Vivi Schlünssen
- Department of Public Health, Section for Environment Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
- National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Vibeke Backer
- Department of Respiratory Medicine, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Anders D. Børglum
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Alle 4, 8000 Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Kaare Christensen
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- The Danish Aging Research Center, Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
- Department of Clinical Biochemistry and Pharmacology, University Hospital, Odense, Denmark
| | - Qihua Tan
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Lene Christiansen
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- The Danish Aging Research Center, Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark
| | - Torben Sigsgaard
- Department of Public Health, Section for Environment Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
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Starnawska A, Tan Q, McGue M, Mors O, Børglum AD, Christensen K, Nyegaard M, Christiansen L. Epigenome-Wide Association Study of Cognitive Functioning in Middle-Aged Monozygotic Twins. Front Aging Neurosci 2017; 9:413. [PMID: 29311901 PMCID: PMC5733014 DOI: 10.3389/fnagi.2017.00413] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/28/2017] [Indexed: 12/22/2022] Open
Abstract
As the world's population ages, the age-related cognitive decline presents a great challenge to world's healthcare systems. One of the molecular mechanisms implicated in cognitive ageing is DNA methylation, an epigenetic modification known to be a key player in memory formation, maintenance, and synaptic plasticity. Using the twin design we performed an epigenome-wide association study (EWAS) in a population of 486 middle-aged monozygotic twins (mean age at follow-up 65.9, SD = 6.1) and correlated their blood DNA methylation to their level (cross-sectional analysis) and change in cognitive abilities over 10 years (longitudinal analysis). We identified several CpG sites where cross-sectional cognitive functioning was associated with DNA methylation levels. The top identified loci were located in ZBTB46 (p = 5.84 × 10-7), and TAF12 (p = 4.91 × 10-7). KEGG's enrichment analyses of the most associated findings identified "Neuroactive ligand-receptor interaction" as the most enriched pathway (p = 0.0098). Change in cognitive functioning over 10 years was associated with DNA methylation levels in AGBL4 (p = 9.01 × 10-7) and SORBS1 (p = 5.28 × 10-6), with the first gene playing an important role in neuronal survival and the latter gene implicated before in Alzheimer's disease and ischemic stroke. Our findings point to an association between changes in DNA methylation of genes related to neuronal survival and change of cognitive functioning in aging individuals.
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Affiliation(s)
- Anna Starnawska
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Qihua Tan
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Matt McGue
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Psychology, University of Minnesota, Minneapolis, MN, United States
| | - Ole Mors
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - Anders D. Børglum
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Kaare Christensen
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
- The Danish Aging Research Center, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark
| | - Mette Nyegaard
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Center for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
| | - Lene Christiansen
- The Danish Twin Registry, Institute of Public Health, University of Southern Denmark, Odense, Denmark
- The Danish Aging Research Center, Institute of Public Health, University of Southern Denmark, Odense, Denmark
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Liu C, Molenaar PCM, Neiderhiser JM. The Impact of Variation in Twin Relatedness on Estimates of Heritability and Environmental Influences. Behav Genet 2017; 48:44-54. [PMID: 29098497 DOI: 10.1007/s10519-017-9875-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 10/03/2017] [Indexed: 11/25/2022]
Abstract
By taking advantage of the natural variation in genetic relatedness among identical (monozygotic: MZ) and fraternal (dizygotic: DZ) twins, twin studies are able to estimate genetic and environmental contributions to complex human behaviors. Recently concerns have been raised about the accuracy of twin studies in light of findings of genetic and epigenetic changes in twins. One of the concerns raised is that MZ twins are not 100% genetically and epigenetically similar because they show variations in their genomes and epigenomes leading to inaccurate estimates of heritability. This article presents findings from a simulation study that examined the degree of bias in estimates of heritability and environmentality when the genetic and epigenetic similarity of MZ twins differs from 1.00 and when the genetic and epigenetic similarity of DZ twins differs from 0.50. The findings suggest that in the standard biometric model when MZ or DZ twin similarity differs from 1.00 or 0.50, respectively, the variance that should be attributed to genetic influences is instead attributed to nonshared environmental influences, thus deflating the estimates of genetic influences and inflating the estimates of nonshared environmental influences. Although estimates of genetic and nonshared environmental influences from the standard biometric model were found to deviate from "true" values, the bias was usually smaller than 10% points indicating that the interpretations of findings from previous twin studies are mostly correct.
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Affiliation(s)
- Chang Liu
- Department of Psychology, The Pennsylvania State University, 431 Moore Building, University Park, PA, 16802, USA.
| | - Peter C M Molenaar
- Department of Human Development and Family Studies, The Pennsylvania State University, 415 BBH Building, University Park, PA, 16802, USA
| | - Jenae M Neiderhiser
- Department of Psychology, The Pennsylvania State University, 431 Moore Building, University Park, PA, 16802, USA
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Epigenetic dysregulation of protocadherins in human disease. Semin Cell Dev Biol 2017; 69:172-182. [PMID: 28694114 DOI: 10.1016/j.semcdb.2017.07.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/12/2022]
Abstract
Protocadherins (Pcdhs) are a group of cell-cell adhesion molecules that are highly expressed in the nervous system and have a major function in dendrite development and neural circuit formation. However, the role protocadherins play in human health and disease remains unclear. Several recent studies have associated epigenetic dysregulation of protocadherins with possible implications for disease pathogenesis. In this review, we briefly recap the various epigenetic mechanisms regulating protocadherin genes, particularly the clustered Pcdhs. We further outline research describing altered epigenetic regulation of protocadherins in neurological and psychiatric disorders, as well as in cancer and during aging. We additionally present preliminary data on DNA methylation dynamics of clustered protocadherins during fetal brain development, as well as the epigenetic differences distinguishing adult neuronal and glial cells. A deeper understanding of the role of protocadherins in disease is crucial for designing novel diagnostic tools and therapies targeting brain disorders.
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Chaumette B, Kebir O, Krebs MO. [Genetics and epigenetics of schizophrenia and other psychoses]. Biol Aujourdhui 2017; 211:69-82. [PMID: 28682228 DOI: 10.1051/jbio/2017015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Indexed: 06/07/2023]
Abstract
Schizophrenia and other psychoses are categorical psychiatric diagnoses corresponding to frequent and heterogeneous disorders. Their physiopathology still remains largely unknown despite numerous recent advances. In particular, the last decade has identified different types of genetic variants, thanks to emergence of high-throughput methods. These methods allow both the identification of rare variants with a large effect such as punctual mutations or copy-number variants and the identification of frequent variants with a limited effect such as polymorphisms. Many impacted genes have been identified showing a very high genetic heterogeneity of psychoses. These genes are overrepresented in synaptic and neurotransmission pathways. Only a small fraction of psychoses could be easily explained by genetics but this screening in clinical practice is important as it can lead to therapeutic challenge or genetic counselling. Nowadays, it is clear that the pathophysiology of the psychoses can only be understood by an integrative approach taking into account the interaction between genes and environment. This interaction could be mediated by the epigenome defined as the modification of gene expression without changes in DNA sequence. Epigenome is stable but could be modified by environmental factors. Several epigenetic mechanisms have been studied in psychosis, in particular the DNA methylation, the modification of histones and the microRNA. All of these mechanisms are under regulation by genetic factors and variants in these epigenetic-involved genes and cofactors have been also associated with schizophrenia. Thus, pathophysiology of psychosis is complex and morestudiesare needed before definitive conclusions. Altogether, the recent advances in the genetics and epigenetics of psychosis are promising and could open the way to a recategorization of these disorders as well as the identification of new therapeutic targets.
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Affiliation(s)
- Boris Chaumette
- Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Oussama Kebir
- INSERM, U894, Laboratoire "Physiopathologie des maladies psychiatriques", Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 102-108 rue de la Santé, 75014 Paris, France Institut de Psychiatrie-GDR 3557, Centre Hospitalier Sainte-Anne, Paris, France
| | - Marie-Odile Krebs
- INSERM, U894, Laboratoire "Physiopathologie des maladies psychiatriques", Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 102-108 rue de la Santé, 75014 Paris, France Institut de Psychiatrie-GDR 3557, Centre Hospitalier Sainte-Anne, Paris, France
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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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Schuebel K, Gitik M, Domschke K, Goldman D. Making Sense of Epigenetics. Int J Neuropsychopharmacol 2016; 19:pyw058. [PMID: 27312741 PMCID: PMC5137275 DOI: 10.1093/ijnp/pyw058] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/10/2016] [Indexed: 01/08/2023] Open
Abstract
The gene-environment interactions that underlie development and progression of psychiatric illness are poorly understood. Despite a century of progress, genetic approaches have failed to identify new treatment modalities, perhaps because of the heterogeneity of the disorders and lack of understanding of mechanisms. Recent exploration into epigenetic mechanisms in health and disease has uncovered changes in DNA methylation and chromatin structure that may contribute to psychiatric disorders. Epigenetic changes suggest a variety of new therapeutic options due to their reversible chemistry. However, distinguishing causal links between epigenetic changes and disease from changes consequent to life experience has remained problematic. Here we define epigenetics and explore aspects of epigenetics relevant to causes and mechanisms of psychiatric disease, and speculate on future directions.
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Affiliation(s)
- Kornel Schuebel
- Laboratory of Neurogenetics and Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland (Drs Schuebel, Gitik, and Goldman); Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (Dr Domschke)
| | - Miri Gitik
- Laboratory of Neurogenetics and Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland (Drs Schuebel, Gitik, and Goldman); Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (Dr Domschke)
| | - Katharina Domschke
- Laboratory of Neurogenetics and Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland (Drs Schuebel, Gitik, and Goldman); Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (Dr Domschke)
| | - David Goldman
- Laboratory of Neurogenetics and Office of the Clinical Director, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland (Drs Schuebel, Gitik, and Goldman); Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany (Dr Domschke).
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Fullard JF, Halene TB, Giambartolomei C, Haroutunian V, Akbarian S, Roussos P. Understanding the genetic liability to schizophrenia through the neuroepigenome. Schizophr Res 2016; 177:115-124. [PMID: 26827128 PMCID: PMC4963306 DOI: 10.1016/j.schres.2016.01.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 01/14/2016] [Accepted: 01/18/2016] [Indexed: 12/17/2022]
Abstract
The Psychiatric Genomics Consortium-Schizophrenia Workgroup (PGC-SCZ) recently identified 108 loci associated with increased risk for schizophrenia (SCZ). The vast majority of these variants reside within non-coding sequences of the genome and are predicted to exert their effects by affecting the mechanism of action of cis regulatory elements (CREs), such as promoters and enhancers. Although a number of large-scale collaborative efforts (e.g. ENCODE) have achieved a comprehensive mapping of CREs in human cell lines or tissue homogenates, it is becoming increasingly evident that many risk-associated variants are enriched for expression Quantitative Trait Loci (eQTLs) and CREs in specific tissues or cells. As such, data derived from previous research endeavors may not capture fully cell-type and/or region specific changes associated with brain diseases. Coupling recent technological advances in genomics with cell-type specific methodologies, we are presented with an unprecedented opportunity to better understand the genetics of normal brain development and function and, in turn, the molecular basis of neuropsychiatric disorders. In this review, we will outline ongoing efforts towards this goal and will discuss approaches with the potential to shed light on the mechanism(s) of action of cell-type specific cis regulatory elements and their putative roles in disease, with particular emphasis on understanding the manner in which the epigenome and CREs influence the etiology of SCZ.
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Affiliation(s)
- John F. Fullard
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tobias B. Halene
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA
| | | | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Genetics and Genomic Science and Institute for Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA.
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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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Lyu N, Guan LL, Ma H, Wang XJ, Wu BM, Shang FH, Wang D, Wen H, Yu X. Failure to Identify Somatic Mutations in Monozygotic Twins Discordant for Schizophrenia by Whole Exome Sequencing. Chin Med J (Engl) 2016; 129:690-5. [PMID: 26960372 PMCID: PMC4804415 DOI: 10.4103/0366-6999.178009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Schizophrenia (SCZ) is a severe, debilitating, and complex psychiatric disorder with multiple causative factors. An increasing number of studies have determined that rare variations play an important role in its etiology. A somatic mutation is a rare form of genetic variation that occurs at an early stage of embryonic development and is thought to contribute substantially to the development of SCZ. The aim of the study was to explore the novel pathogenic somatic single nucleotide variations (SNVs) and somatic insertions and deletions (indels) of SCZ. Methods: One Chinese family with a monozygotic (MZ) twin pair discordant for SCZ was included. Whole exome sequencing was performed in the co-twin and their parents. Rigorous filtering processes were conducted to prioritize pathogenic somatic variations, and all identified SNVs and indels were further confirmed by Sanger sequencing. Results: One somatic SNV and two somatic indels were identified after rigorous selection processes. However, none was validated by Sanger sequencing. Conclusions: This study is not alone in the failure to identify pathogenic somatic variations in MZ twins, suggesting that exonic somatic variations are extremely rare. Further efforts are warranted to explore the potential genetic mechanism of SCZ.
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Affiliation(s)
| | - Li-Li Guan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
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Impact of Early Environment on Children's Mental Health: Lessons From DNA Methylation Studies With Monozygotic Twins. Twin Res Hum Genet 2015; 18:623-34. [DOI: 10.1017/thg.2015.84] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Over the past decade, epigenetic analyses have made important contributions to our understanding of healthy development and a wide variety of adverse conditions such as cancer and psychopathology. There is increasing evidence that DNA methylation is a mechanism by which environmental factors influence gene transcription and, ultimately, phenotype. However, differentiating the effects of the environment from those of genetics on DNA methylation profiles remains a significant challenge. Monozygotic (MZ) twin study designs are unique in their ability to control for genetic differences because each pair of MZ twins shares essentially the same genetic sequence with the exception of a small number of de novo mutations and copy number variations. Thus, differences within twin pairs in gene expression and phenotype, including behavior, can be attributed in the majority of cases to environmental effects rather than genetic influence. In this article, we review the literature showing how MZ twin designs can be used to study basic epigenetic principles, contributing to understanding the role of early in utero and postnatal environmental factors on the development of psychopathology. We also highlight the importance of initiating longitudinal and experimental studies with MZ twins during pregnancy. This approach is especially important to identify: (1) critical time periods during which the early environment can impact brain and mental health development, and (2) the specific mechanisms through which early environmental effects may be mediated. These studies may inform the optimum timing and design for early preventive interventions aimed at reducing risk for psychopathology.
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Gumerov V, Hegyi H. MicroRNA-derived network analysis of differentially methylated genes in schizophrenia, implicating GABA receptor B1 [GABBR1] and protein kinase B [AKT1]. Biol Direct 2015; 10:59. [PMID: 26450699 PMCID: PMC4598960 DOI: 10.1186/s13062-015-0089-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/28/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND While hundreds of genes have been implicated already in the etiology of schizophrenia, the exact cause is not known or the disease is considered multigenic in origin. Recent discoveries of new types of RNAs and the gradual elimination of the "junk DNA" hypothesis refocused the attention on the noncoding part of the human genome. Here we re-analyzed a recent dataset of differentially methylated genes from schizophrenic patients and cross-tabulated them with cis regulatory and repetitive elements and microRNAs known to be involved in schizophrenia. RESULTS We found that the number of schizophrenia-related (SZ) microRNA targets follows a scale-free distribution with several microRNA hubs and that schizophrenia-related microRNAs with shared targets form a small-world network. The top ten microRNAs with the highest number of SZ gene targets regulate approximately 80 % of all microRNA-regulated genes whereas the top two microRNAs regulate 40-52 % of all such genes. We also found that genes that are regulated by the same microRNAs tend to have more protein-protein interactions than randomly selected schizophrenia genes. This highlights the role microRNAs possibly play in coordinating the abundance of interacting proteins, an important function that has not been sufficiently explored before. The analysis revealed that GABBR1 is regulated by both of the top two microRNAs and acts as a hub by interacting with many schizophrenia-related genes and sharing several types of transcription-binding sites with its interactors. We also found that differentially methylated repetitive elements are significantly more methylated in schizophrenia, pointing out their potential role in the disease. CONCLUSIONS We find that GABBR1 has a central importance in schizophrenia, even if no direct cause and effect have been shown for it for the time. In addition to being a hub in microRNA-derived regulatory pathways and protein-protein interactions, its centrality is also supported by the high number of cis regulatory elements and transcription factor-binding sites that regulate its transcription. These findings are in line with several genome-wide association studies that repeatedly find the major histocompatibility region (where GABBR1 is located) to have the highest number of single nucleotide polymorphisms in schizophrenics. Our model also offers an explanation for the downregulation of protein kinase B, another consistent finding in schizophrenic patients. Our observations support the notion that microRNAs fine-tune the amount of proteins acting in the same biological pathways in schizophrenia, giving further support to the emerging theory of competing endogenous RNAs.
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Affiliation(s)
- Vadim Gumerov
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic.
| | - Hedi Hegyi
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic.
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Melka MG, Castellani CA, O'Reilly R, Singh SM. Insights into the origin of DNA methylation differences between monozygotic twins discordant for schizophrenia. J Mol Psychiatry 2015; 3:7. [PMID: 26137221 PMCID: PMC4487197 DOI: 10.1186/s40303-015-0013-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/15/2015] [Indexed: 12/22/2022] Open
Abstract
Background DNA methylation differences between monozygotic twins discordant for schizophrenia have been previously reported. However, the origin of methylation differences between monozygotic twins discordant for schizophrenia is not clear. The findings here argue that all DNA methylation differences may not necessarily represent the cause of the disease; rather some may result from the effect of antipsychotics. Methods Methylation differences in rat brain regions and also in two pairs of unrelated monozygotic twins discordant for schizophrenia have been studied using genome-wide DNA methylation arrays at Arraystar Inc. (Rockville, Maryland, USA). The identified gene promoters showing significant alterations to DNA methylation were then further characterized using ingenuity pathway analysis (Ingenuity System Inc, CA, USA). Results Pathway analysis of the most significant gene promoter hyper/hypomethylation revealed a significant enrichment of DNA methylation changes in biological networks and pathways directly relevant to neural development and psychiatric disorders. These included HIPPO signaling (p = 3.93E-03) and MAPK signaling (p = 4.27E-03) pathways involving hypermethylated genes in schizophrenia-affected patients as compared to their unaffected co-twins. Also, a number of significant pathways and networks involving genes with hypomethylated gene promoters have been identified. These included CREB signaling in neurons (p = 1.53E-02), Dopamine-DARPP32 feedback in cAMP signaling (p = 7.43E-03) and Ephrin receptors (p = 1.13E-02). Further, there was significant enrichment for pathways involved in nervous system development and function (p = 1.71E-03-4.28E-02). Conclusion The findings highlight the significance of antipsychotic drugs on DNA methylation in schizophrenia patients. The unique pathways affected by DNA methylation in the two pairs of monozygotic twins suggest that patient-specific pathways are responsible for the disease; suggesting that patient-specific treatment strategies may be necessary in treating the disorder. The study reflects the need for developing personalized medicine approaches that take into consideration epigenetic variations between patients. Electronic supplementary material The online version of this article (doi:10.1186/s40303-015-0013-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Melkaye G Melka
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Christina A Castellani
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Richard O'Reilly
- Department of Psychiatry, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Shiva M Singh
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
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