DNA modifications in schizophrenia

2020 ◽  
pp. 177-183
Author(s):  
Ehsan Pishva ◽  
Bart P. F. Rutten

Interplay between genetic and environmental factors plays a major role in shaping the neurodevelopmental origins of schizophrenia. Epigenetic processes act to dynamically control gene expression and are known to regulate key neurobiological and cognitive processes in the brain. Along with mediating the effects of environmental risk factors on the development of disease, epigenetic processes play a central role in the differentiation and development of the human brain. Therefore, investigating epigenetic variations associated with schizophrenia may shed new light on our understanding about the developmental and environmental origins of schizophrenia. DNA methylation is the best-characterized epigenetic modification, playing a role in regulating gene expression, alternative splicing and other transcriptional processes such as X-chromosome inactivation and genomic imprinting. This chapter discusses the evidence to support a role for DNA modifications in schizophrenia, and highlights the opportunities and challenges of ongoing studies.

2019 ◽  
Vol 97 (4) ◽  
pp. 345-356 ◽  
Author(s):  
Stefania Ciafrè ◽  
Valentina Carito ◽  
Giampiero Ferraguti ◽  
Antonio Greco ◽  
George N. Chaldakov ◽  
...  

This work highlights recent studies in epigenetic mechanisms that play a role in alcoholism, which is a complex multifactorial disorder. There is a large body of evidence showing that alcohol can modify gene expression through epigenetic processes, namely DNA methylation and nucleosomal remodeling via histone modifications. In that regard, chronic exposure to ethanol modifies DNA and histone methylation, histone acetylation, and microRNA expression. The alcohol-mediated chromatin remodeling in the brain promotes the transition from use to abuse and addiction. Unravelling the multiplex pattern of molecular modifications induced by ethanol could support the development of new therapies for alcoholism and drug addiction targeting epigenetic processes.


2021 ◽  
Author(s):  
Pavel V. Mazin ◽  
Philipp Khaitovich ◽  
Margarida Cardoso-Moreira ◽  
Henrik Kaessmann

AbstractAlternative splicing (AS) is pervasive in mammalian genomes, yet cross-species comparisons have been largely restricted to adult tissues and the functionality of most AS events remains unclear. We assessed AS patterns across pre- and postnatal development of seven organs in six mammals and a bird. Our analyses revealed that developmentally dynamic AS events, which are especially prevalent in the brain, are substantially more conserved than nondynamic ones. Cassette exons with increasing inclusion frequencies during development show the strongest signals of conserved and regulated AS. Newly emerged cassette exons are typically incorporated late in testis development, but those retained during evolution are predominantly brain specific. Our work suggests that an intricate interplay of programs controlling gene expression levels and AS is fundamental to organ development, especially for the brain and heart. In these regulatory networks, AS affords substantial functional diversification of genes through the generation of tissue- and time-specific isoforms from broadly expressed genes.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Chen Yao ◽  
Roby Joehanes ◽  
Rory Wilson ◽  
Toshiko Tanaka ◽  
Luigi Ferrucci ◽  
...  

Abstract Background DNA methylation is a key epigenetic modification that can directly affect gene regulation. DNA methylation is highly influenced by environmental factors such as cigarette smoking, which is causally related to chronic obstructive pulmonary disease (COPD) and lung cancer. To date, there have been few large-scale, combined analyses of DNA methylation and gene expression and their interrelations with lung diseases. Results We performed an epigenome-wide association study of whole blood gene expression in ~ 6000 individuals from four cohorts. We discovered and replicated numerous CpGs associated with the expression of cis genes within 500 kb of each CpG, with 148 to 1,741 cis CpG-transcript pairs identified across cohorts. We found that the closer a CpG resided to a transcription start site, the larger its effect size, and that 36% of cis CpG-transcript pairs share the same causal genetic variant. Mendelian randomization analyses revealed that hypomethylation and lower expression of CHRNA5, which encodes a smoking-related nicotinic receptor, are causally linked to increased risk of COPD and lung cancer. This putatively causal relationship was further validated in lung tissue data. Conclusions Our results provide a large and comprehensive association study of whole blood DNA methylation with gene expression. Expression platform differences rather than population differences are critical to the replication of cis CpG-transcript pairs. The low reproducibility of trans CpG-transcript pairs suggests that DNA methylation regulates nearby rather than remote gene expression. The putatively causal roles of methylation and expression of CHRNA5 in relation to COPD and lung cancer provide evidence for a mechanistic link between patterns of smoking-related epigenetic variation and lung diseases, and highlight potential therapeutic targets for lung diseases and smoking cessation.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 214.1-214
Author(s):  
I. Arias de la Rosa ◽  
M. D. López Montilla ◽  
J. Rodríguez ◽  
E. Ballester ◽  
C. Torres-Granados ◽  
...  

Background:Cardiovascular risk factors are increased in Psoriatic Arthritis (PsA). In fact, around 60% out of PsA patients display insulin resistance (IR), a hallmark of metabolic syndrome, which might significantly contribute to the cardiovascular disease. Latest studies suggested that inflammatory and metabolic disorders may be under epigenetic control, including DNA methylation. DNA methylation is an unexplored area in the field of PsA.Objectives:To study the alterations in the genome-wide DNA methylation profile of CD4+T cells from PsA patients and its relationship with its pathology and the risk of cardiovascular comorbidity.Methods:Twenty healthy controls (HC) and 20 PsA patients were included in the study. PsA patients were classified into insulin resistant and non-insulin resistant according to HOMA-IR index. CD4+T lymphocytes were isolated from peripheral blood by positive immunomagnetic selection. The Illumina Infinium MethylationEPIC Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpGs (TSS1500, TSS200, 5UTR, 3UTR, first exon, gene body). Beta values (β) estimating methylation levels were obtained at each CpG site, and differentially methylated genes (DMG) between PsA and HC were identified. Functional classification of these genes was carried out through gene ontology analysis (PANTHER database). Gene expression analysis of the selected genes was also evaluated by RT-PCR. Vascular parameters including carotid intima-media thickness (cIMT) and endothelial function was analyzed by ecodoppler and periflux respectively.Results:The genome-wide methylation analysis identified 112 DMGs including 41 hypomethylated and 71 hypermethylated. These differentially methylated genes were enriched with several signaling pathways and disease categories including immune response, metabolic processes, oxidative stress, vascular and inflammatory pathways. The altered gene expression of selected genes with altered methylation levels in PsA was also validated. Correlation and association analysis of these DMGs with clinical and analytical variables, cardiovascular risk factors and endothelial microvascular function revealed that the degree of methylation of these genes was significantly associated with cIMT (IGF1R, NDRG3, SMYD3, HLA-DRB1, WDR70), arterial pressure (METT5D1, NRDG3, ADAM17, SMYD3, WNK1, CBX1), insulin resistance (AKAP13, SEMA6D, PLCB1), altered lipid profile and atherogenic index (MYBL1, METT5D1, MAN2A1, SLC1A7, SEMA6D, PLCB1, TLK1, SDK1, CBX1), inflammation (MYBL1, NDUFA5, METT5D1, SEMA6D, PLCB1, TLK1), and endothelial dysfunction (ADAMST10, GPCPD1, CCDC88A). In addition, this analysis also identified 435 DMGs including 280 hypomethylated and 155 hypermethylated in CD4+T cells from IR-PsA vs non IR-PsA patients. Between these two groups of PsA patients, CHUK, SERINC1, RUNX1, TTYH2, TXNDC11, FAF1, BICD1, SCD5, PDE5A, FAS, NFIA and GRP75 displayed the most significantly altered methylation, suggesting the role of these genes in the metabolic complications associated with PsA.Conclusion:These findings help our understanding of the pathogenesis of PsA and advance epigenetic studies in regards to this disease and the cardiometabolic comorbidities associated. Funded by ISCIII (PI17/01316 and RIER RD16/0012/0015) co-funded with FEDER.Disclosure of Interests:Iván Arias de la Rosa: None declared, María Dolores López Montilla Speakers bureau: Celgene, Javier Rodríguez: None declared, Esteban Ballester: None declared, Carmen Torres-Granados: None declared, Carlos Perez-Sanchez: None declared, Maria del Carmen Abalos-Aguilera: None declared, Gómez García Ignacio: None declared, Desiree Ruiz: None declared, Alejandra M. Patiño-Trives: None declared, María Luque-Tévar: None declared, Eduardo Collantes-Estévez Grant/research support from: ROCHE and Pfizer., Speakers bureau: ROCHE, Lilly, Bristol and Celgene., Chary Lopez-Pedrera Grant/research support from: ROCHE and Pfizer., Alejandro Escudero Contreras Grant/research support from: ROCHE and Pfizer, Speakers bureau: ROCHE, Lilly, Bristol and Celgene., Nuria Barbarroja Puerto Grant/research support from: ROCHE and Pfizer., Speakers bureau: ROCHE and Celgene.


Author(s):  
Charlotte A.M. Cecil

The biopsychosocial (BPS) model of psychiatry has had a major impact on our modern conceptualization of mental illness as a complex, multi-determined phenomenon. Yet, interdisciplinary BPS work remains the exception, rather than the rule in psychiatry. It has been suggested that this may stem in part from a failure of the BPS model to clearly delineate the mechanisms through which biological, psychological, and social factors co-act in the development of mental illness. This chapter discusses how epigenetic processes that regulate gene expression, such as DNA methylation, are fast emerging as a candidate mechanism for BPS interactions, with potentially widespread implications for the way that psychiatric disorders are understood, assessed, and, perhaps in future, even treated.


Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 135 ◽  
Author(s):  
Zhongyuan Lin ◽  
Meihui Liu ◽  
Rebecca Njeri Damaris ◽  
Tonny Maraga Nyong’a ◽  
Dingding Cao ◽  
...  

DNA methylation is a vital epigenetic modification. Methylation has a significant effect on the gene expression influencing the regulation of different physiological processes. Current studies on DNA methylation have been conducted on model plants. Lotus (Nelumbo nucifera) is a basic eudicot exhibiting variations during development, especially in flower formation. DNA methylation profiling was conducted on different flower tissues of lotuses through whole genome bisulfite sequencing (WGBS) to investigate the effects of DNA methylation on its stamen petaloid. A map of methylated cytosines at the single base pair resolution for the lotus was constructed. When the stamen was compared with the stamen petaloid, the DNA methylation exhibited a global decrease. Genome-wide relationship analysis between DNA methylation and gene expression identified 31 different methylation region (DMR)-associated genes, which might play crucial roles in floral organ formation, especially in the stamen petaloid. One out of 31 DMR-associated genes, NNU_05638 was homolog with Plant U-box 33 (PUB33). The DNA methylation status of NNU_05638 promoter was distinct in three floral organs, which was confirmed by traditional bisulfite sequencing. These results provide further insights about the regulation of stamen petaloids at the epigenetic level in lotus.


2020 ◽  
Vol 10 (9) ◽  
pp. 3435-3443
Author(s):  
Jian Liu ◽  
Laureline Mosser ◽  
Catherine Botanch ◽  
Jean-Marie François ◽  
Jean-Pascal Capp

Abstract Chromatin structure clearly modulates gene expression noise, but the reverse influence has never been investigated, namely how the cell-to-cell expression heterogeneity of chromatin modifiers may generate variable rates of epigenetic modification. Sir2 is a well-characterized histone deacetylase of the Sirtuin family. It strongly influences chromatin silencing, especially at telomeres, subtelomeres and rDNA. This ability to influence epigenetic landscapes makes it a good model to study the largely unexplored interplay between gene expression noise and other epigenetic processes leading to phenotypic diversification. Here, we addressed this question by investigating whether noise in the expression of SIR2 was associated with cell-to-cell heterogeneity in the frequency of epigenetic silencing at subtelomeres in Saccharomyces cerevisiae. Using cell sorting to isolate subpopulations with various expression levels, we found that heterogeneity in the cellular concentration of Sir2 does not lead to heterogeneity in the epigenetic silencing of subtelomeric URA3 between these subpopulations. We also noticed that SIR2 expression noise can generate cell-to-cell variability in viability, with lower levels being associated with better viability. This work shows that SIR2 expression fluctuations are not sufficient to generate cell-to-cell heterogeneity in the epigenetic silencing of URA3 at subtelomeres in Saccharomyces cerevisiae but can strongly affect cellular viability.


2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Yahui Shi ◽  
Jinfen Wei ◽  
Zixi Chen ◽  
Yuchen Yuan ◽  
Xingsong Li ◽  
...  

Background. Cancer cells undergo various rewiring of metabolism and dysfunction of epigenetic modification to support their biosynthetic needs. Although the major features of metabolic reprogramming have been elucidated, the global metabolic genes linking epigenetics were overlooked in pan-cancer. Objectives. Identifying the critical metabolic signatures with differential expressions which contributes to the epigenetic alternations across cancer types is an urgent issue for providing the potential targets for cancer therapy. Method. The differential gene expression and DNA methylation were analyzed by using the 5726 samples data from the Cancer Genome Atlas (TCGA). Results. Firstly, we analyzed the differential expression of metabolic genes and found that cancer underwent overall metabolism reprogramming, which exhibited a similar expression trend with the data from the Gene Expression Omnibus (GEO) database. Secondly, the regulatory network of histone acetylation and DNA methylation according to altered expression of metabolism genes was summarized in our results. Then, the survival analysis showed that high expression of DNMT3B had a poorer overall survival in 5 cancer types. Integrative altered methylation and expression revealed specific genes influenced by DNMT3B through DNA methylation across cancers. These genes do not overlap across various cancer types and are involved in different function annotations depending on the tissues, which indicated DNMT3B might influence DNA methylation in tissue specificity. Conclusions. Our research clarifies some key metabolic genes, ACLY, SLC2A1, KAT2A, and DNMT3B, which are most disordered and indirectly contribute to the dysfunction of histone acetylation and DNA methylation in cancer. We also found some potential genes in different cancer types influenced by DNMT3B. Our study highlights possible epigenetic disorders resulting from the deregulation of metabolic genes in pan-cancer and provides potential therapy in the clinical treatment of human cancer.


2020 ◽  
Vol 38 (5_suppl) ◽  
pp. 25-25
Author(s):  
Yuanyuan Shen ◽  
Justin Hummel ◽  
Isabel Cristina Trindade ◽  
Christos Papageorgiou ◽  
Chi-Ren Shyu ◽  
...  

25 Background: Low cytotoxic T lymphocyte (CTLs) infiltration in colorectal cancer (CRC) tumors is a challenge to treatment with immune checkpoint inhibitors. Consensus molecular subtypes (CMS) classify patients based on tumor attributes, and CMS1 patients include the majority of patients with high CTL infiltration and “inflamed” tumors. Epigenetic modification plays a critical role in gene expression and therapy resistance. Therefore, in this study we compared DNA methylation, gene expression, and CTL infiltration of CMS1 patients to other CMS groups to determine targets for improving immunotherapy in CRC. Methods: RNA-seq (n = 511) and DNA methylation (n = 316) from The Cancer Genome Atlas databases were used to determine gene expression and methylation profiles based on CMSs. CMS1 was used as a reference and compared to other subtypes (CMS2-4). Microenvironment Cell Populations- counter (MCPcounter) was used to determine tumor CTL infiltration. Genes with significantly different expression (p < 0.01, LogFC≥|1.5|) and difference of mean methylation β value ≥|0.25| were integrated for Pearson correlation coefficient analysis with MCPcounter score (r > |0.7|). Results: Comparing CMS1 and CMS2, ARHGAP9, TBX21, and LAG3 were differentially methylated and correlated with CTL scores. ARHGAP9 and TBX21 were decreased and hypomethylated in CMS2. Comparing CMS1 and CMS3, ARHGAP9, TBX21, FMNL1, HLA-DPB1, and STX11 were downregulated in CMS3 and highly correlated with CTL scores. ARHGAP9, FMNL1, HLA-DPB1, and STX11 were hypomethylated in CMS3 and TBX21 was methylated in both, but had a higher methylation ratio in CMS1. Comparing CMS1 and CMS4, TBX21 was the only gene downregulated, hypomethylated, and highly correlated with CTL scores in CMS4 patients. Conclusions: We found six genes differentially expressed, differentially methylated, and highly correlated with CTL infiltration when comparing CMS1 to other CMS groups. Specifically, TBX21 was the only gene highly correlated with CTL scores with differential gene expression and methylation in CMS2-4 when compared to CMS1. Thus, T-bet may be a critical regulator of T cell responses in CRC.


2020 ◽  
Vol 10 (4) ◽  
pp. 260-266
Author(s):  
Sagar. S. Waghmare ◽  
O.G. Bhusnure ◽  
M. R. Mali ◽  
S.T. Mule

For a long time scientists have tried to describe disorders are due to genetic as well as environmental factors. In the past few years, revolution in technology that has made it possible to decipher the human genome. Epigenetics explains the capability gene expression regulation without modifying the genetic sequence. Epigenetic mechanisms are rooted changes in molecules, or nuclear characteristics that can alter gene expression without altering the sequences of DNA, i.e. DNA methylation, histone modification, and non-coding RNAs. Learning of the fundamental epigenetic modification allowing gene expression as well as cellular phenotype are advanced that novel insights into the epigenetic control of cardiovascular disease, hepatic disease, as well as chronic kidney disease are now emerging. From a half of century ago, in human disease the role of epigenetics has been considered. This subject has attracted many interests in the past decade, especially in complicated diseases like cardiovascular disease, hepatic disease as well as chronic kidney disease. This review first illustrates the history and classification of epigenetic modifications and the factors (i.e. genetic, environment, dietary, thought process and lifestyle) affecting to the epigenetics mechanisms. Likewise, the epigenetics role in human diseases is think out by targeting on some diseases and at the end, we have given the future perspective of this field. This review article provides concepts with some examples to describe a broad view of distinct aspects of epigenetics in biology and human diseases. Keywords: - Epigenetics, DNA methylation, Histone modifications, microRNAs and Gene expression and Disease.


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