scholarly journals Multi-Omics Signatures of Alcohol Use Disorder in the Dorsal and Ventral Striatum

Author(s):  
Lea Zillich ◽  
Eric Poisel ◽  
Josef Frank ◽  
Jerome C. Foo ◽  
Marion M. Friske ◽  
...  

Alcohol Use Disorder (AUD) is a major contributor to global mortality and morbidity. Postmortem human brain tissue enables the investigation of molecular mechanisms of AUD in the neurocircuitry of addiction. We aimed to identify differentially expressed (DE) genes in the ventral and dorsal striatum between individuals with AUD and controls, and to integrate the results with findings from genome- and epigenome-wide association studies (GWAS/EWAS) to identify functionally relevant molecular mechanisms of AUD. DNA-methylation and gene expression (RNA-seq) data was generated from postmortem brain samples of 48 individuals with AUD and 51 controls from the ventral striatum (VS) and the dorsal striatal regions caudate nucleus (CN) and putamen (PUT). We identified DE genes using DESeq2, performed gene-set enrichment analysis (GSEA), and tested enrichment of DE genes in results of GWASs using MAGMA. Weighted correlation network analysis (WGCNA) was performed for DNA-methylation and gene expression data and gene overlap was tested. In the dorsal striatum, we discovered differential expression (FDR<0.05) for a total of 50 genes. In the VS, DE genes at FDR<0.25 were overrepresented in a recent GWAS of problematic alcohol use. The ARHGEF15 gene was upregulated in all three brain regions. GSEA in CN and VS pointed towards cell-structure associated GO-terms and in PUT towards immune pathways. The WGCNA modules most strongly associated with AUD showed strong enrichment for immune response and inflammation pathways. Our integrated analysis of multi-omics data sets provides further evidence for the importance of immune-and inflammation-related processes in AUD.

2020 ◽  
Author(s):  
Chris Bryan ◽  
Li Lin ◽  
Junkai Xie ◽  
Janiel Ahkin Chin Tai ◽  
Katharine A. Horzmann ◽  
...  

ABSTRACTAtrazine (ATZ) is one of the most commonly used herbicides in the United States. Previous studies have hypothesized the role of ATZ as an endocrine disruptor (EDC), and developmental exposure to ATZ has been shown to lead to behavioral and morphological alterations. Specific epigenetic mechanisms responsible for these alterations, however, are yet to be elucidated. In this study, we exposed zebrafish embryos to 0.3, 3, and 30 ppb (µg/L) of ATZ for 72 hours post fertilization. We performed whole-genome bisulfite sequencing (WGBS) to assess the effects of developmental ATZ exposure on DNA methylation in female fish brains. The number of differentially methylated genes (DMG) increase with increasing dose of treatments. DMGs are enriched in neurological pathways with extensive methylation changes consistently observed in neuroendocrine and reproductive pathways. To assess the effects of DNA methylation on gene expression, we integrated our data with transcriptomic data. Four genes, namely CHD9, FRAS1, PID1, and PCLO, were differentially expressed and methylated in each dose. Overall, this study identifies specific genes and pathways with aberrant methylation and expression following ATZ exposure as targets to elucidate the molecular mechanisms of ATZ toxicity and presents ATZ-induced site-specific DNA methylation as a potential mechanism driving aberrant gene expression.


2017 ◽  
Vol 225 (3) ◽  
pp. 232-243 ◽  
Author(s):  
Alena Becker ◽  
Martin Fungisai Gerchen ◽  
Martina Kirsch ◽  
Bettina Ubl ◽  
Sivaniya Subramaniapillai ◽  
...  

Abstract. Neurobiological research indicates that altered reward processing is among the most promising risk mechanisms in alcohol use disorder and depression. To elucidate differences and similarities between both disorders, we investigated clinical patients and at-risk individuals in two studies using a functional magnetic resonance imaging (fMRI) monetary reward paradigm. In the first study, alcohol use disorder patients compared to depressed and healthy individuals showed increased activation of the ventral striatum during reward anticipation. In contrast, both patient groups showed reduced frontostriatal connectivity compared to controls. In the second study, at-risk comorbid individuals showed decreased activation in the dorsal striatum along with decreased frontostriatal connectivity. While the connectivity results replicate the common pattern found for the patient groups, the activation results indicate a more depression-related pattern in individuals prone to developing both disorders. In conclusion, frontostriatal connectivity might be a promising transdiagnostic marker for depression, alcohol use disorder, and their comorbidity.


Author(s):  
Damian Karl ◽  
J. Malte Bumb ◽  
Patrick Bach ◽  
Christina Dinter ◽  
Anne Koopmann ◽  
...  

Abstract Rationale Alcohol use disorder is a common and devastating mental illness for which satisfactory treatments are still lacking. Nalmefene, as an opioid receptor modulator, could pharmacologically support the reduction of drinking by reducing the (anticipated) rewarding effects of alcohol and expanding the range of treatment options. It has been hypothesized that nalmefene acts via an indirect modulation of the mesolimbic reward system. So far, only a few imaging findings on the neuronal response to nalmefene are available. Objectives We tested the effect of a single dose of 18 mg nalmefene on neuronal cue-reactivity in the ventral and dorsal striatum and subjective craving. Methods Eighteen non-treatment-seeking participants with alcohol use disorder (67% male, M = 50.3 ± 13.9 years) with a current high-risk drinking level (M = 76.9 ± 52 g of pure alcohol per day) were investigated using a cue-reactivity task during functional magnetic resonance imaging (fMRI) in a double-blind, placebo-controlled, cross-over study/design. In addition, self-reported craving was assessed before and after exposure to alcohol cues. Results An a priori defined region of interest (ROI) analysis of fMRI data from 15 participants revealed that nalmefene reduced alcohol cue-reactivity in the ventral, but not the dorsal striatum. Additionally, the subjective craving was significantly reduced after the cue-reactivity task under nalmefene compared to placebo. Conclusion In the present study, reduced craving and cue-reactivity to alcohol stimuli in the ventral striatum by nalmefene indicates a potential anti-craving effect of this drug via attenuation of neural alcohol cue-reactivity.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Joel A. Tripp ◽  
Alejandro Berrio ◽  
Lisa A. McGraw ◽  
Mikhail V. Matz ◽  
Jamie K. Davis ◽  
...  

Abstract Background Pair bonding with a reproductive partner is rare among mammals but is an important feature of human social behavior. Decades of research on monogamous prairie voles (Microtus ochrogaster), along with comparative studies using the related non-bonding meadow vole (M. pennsylvanicus), have revealed many of the neural and molecular mechanisms necessary for pair-bond formation in that species. However, these studies have largely focused on just a few neuromodulatory systems. To test the hypothesis that neural gene expression differences underlie differential capacities to bond, we performed RNA-sequencing on tissue from three brain regions important for bonding and other social behaviors across bond-forming prairie voles and non-bonding meadow voles. We examined gene expression in the amygdala, hypothalamus, and combined ventral pallidum/nucleus accumbens in virgins and at three time points after mating to understand species differences in gene expression at baseline, in response to mating, and during bond formation. Results We first identified species and brain region as the factors most strongly associated with gene expression in our samples. Next, we found gene categories related to cell structure, translation, and metabolism that differed in expression across species in virgins, as well as categories associated with cell structure, synaptic and neuroendocrine signaling, and transcription and translation that varied among the focal regions in our study. Additionally, we identified genes that were differentially expressed across species after mating in each of our regions of interest. These include genes involved in regulating transcription, neuron structure, and synaptic plasticity. Finally, we identified modules of co-regulated genes that were strongly correlated with brain region in both species, and modules that were correlated with post-mating time points in prairie voles but not meadow voles. Conclusions These results reinforce the importance of pre-mating differences that confer the ability to form pair bonds in prairie voles but not promiscuous species such as meadow voles. Gene ontology analysis supports the hypothesis that pair-bond formation involves transcriptional regulation, and changes in neuronal structure. Together, our results expand knowledge of the genes involved in the pair bonding process and open new avenues of research in the molecular mechanisms of bond formation.


Author(s):  
Soundarya Soundararajan ◽  
Arpana Agrawal ◽  
Meera Purushottam ◽  
Shravanthi Daphne Anand ◽  
Bhagyalakshmi Shankarappa ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Federico Tinarelli ◽  
Elena Ivanova ◽  
Ilaria Colombi ◽  
Erica Barini ◽  
Edoardo Balzani ◽  
...  

Abstract Background DNA methylation has emerged as an important epigenetic regulator of brain processes, including circadian rhythms. However, how DNA methylation intervenes between environmental signals, such as light entrainment, and the transcriptional and translational molecular mechanisms of the cellular clock is currently unknown. Here, we studied the after-hours mice, which have a point mutation in the Fbxl3 gene and a lengthened circadian period. Methods In this study, we used a combination of in vivo, ex vivo and in vitro approaches. We measured retinal responses in Afh animals and we have run reduced representation bisulphite sequencing (RRBS), pyrosequencing and gene expression analysis in a variety of brain tissues ex vivo. In vitro, we used primary neuronal cultures combined to micro electrode array (MEA) technology and gene expression. Results We observed functional impairments in mutant neuronal networks, and a reduction in the retinal responses to light-dependent stimuli. We detected abnormalities in the expression of photoreceptive melanopsin (OPN4). Furthermore, we identified alterations in the DNA methylation pathways throughout the retinohypothalamic tract terminals and links between the transcription factor Rev-Erbα and Fbxl3. Conclusions The results of this study, primarily represent a contribution towards an understanding of electrophysiological and molecular phenotypic responses to external stimuli in the Afh model. Moreover, as DNA methylation has recently emerged as a new regulator of neuronal networks with important consequences for circadian behaviour, we discuss the impact of the Afh mutation on the epigenetic landscape of circadian biology.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Derek Van Booven ◽  
Mengying Li ◽  
J. Sunil Rao ◽  
Ilya O. Blokhin ◽  
R. Dayne Mayfield ◽  
...  

AbstractAlcohol use disorder (AUD) is a widespread disease leading to the deterioration of cognitive and other functions. Mechanisms by which alcohol affects the brain are not fully elucidated. Splicing constitutes a nuclear process of RNA maturation, which results in the formation of the transcriptome. We tested the hypothesis as to whether AUD impairs splicing in the superior frontal cortex (SFC), nucleus accumbens (NA), basolateral amygdala (BLA), and central nucleus of the amygdala (CNA). To evaluate splicing, bam files from STAR alignments were indexed with samtools for use by rMATS software. Computational analysis of affected pathways was performed using Gene Ontology Consortium, Gene Set Enrichment Analysis, and LncRNA Ontology databases. Surprisingly, AUD was associated with limited changes in the transcriptome: expression of 23 genes was altered in SFC, 14 in NA, 102 in BLA, and 57 in CNA. However, strikingly, mis-splicing in AUD was profound: 1421 mis-splicing events were detected in SFC, 394 in NA, 1317 in BLA, and 469 in CNA. To determine the mechanism of mis-splicing, we analyzed the elements of the spliceosome: small nuclear RNAs (snRNAs) and splicing factors. While snRNAs were not affected by alcohol, expression of splicing factor heat shock protein family A (Hsp70) member 6 (HSPA6) was drastically increased in SFC, BLA, and CNA. Also, AUD was accompanied by aberrant expression of long noncoding RNAs (lncRNAs) related to splicing. In summary, alcohol is associated with genome-wide changes in splicing in multiple human brain regions, likely due to dysregulation of splicing factor(s) and/or altered expression of splicing-related lncRNAs.


2018 ◽  
Vol 13 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Xiaowu Chen ◽  
Yonghua Zhao ◽  
Yudong He ◽  
Jinliang Zhao

AbstractSkewed sex development is prevalent in fish hybrids. However, the histological observation and molecular mechanisms remain elusive. In this study, we showed that the interspecific hybrids of the two fish species, Oreochromis niloticus and Oreochromis aureus, had a male ratio of 98.02%. Microscopic examination revealed that the gonads of both male and female hybrids were developmentally retarded. Compared with the ovaries, the testes of both O. niloticus and hybrids showed higher DNA methylation level in two selected regions in the promoter of cyp19a, the gonadal aromatase gene that converts androgens into estrogens, cyp19a showed higher level gene expression in the ovary than in the testis in both O. niloticus and hybrid tilapia. Methylation and gene expression level of cyp19a were negative correlation between the testis and ovary. Gene transcription was suppressed by the methylation of the cyp19a promoter in vitro. While there is no obvious difference of the methylation level in testis or ovary between O. niloticus and hybrids. Thus, the DNA methylation of the promoter of cyp19a may be an essential component of the sex maintenance, but not a determinant of high male ratio and developmental retardation of gonads in tilapia hybrids.


Author(s):  
Eleonora Gatta ◽  
Alessandro Guidotti ◽  
Vikram Saudagar ◽  
Dennis R Grayson ◽  
Dario Aspesi ◽  
...  

Abstract Background Alcohol use disorder (AUD) is a chronic relapsing brain disorder. GABAA receptor (GABAAR) subunits are a target for the pharmacological effects of alcohol. Neurosteroids play an important role in the fine-tuning of GABAAR function in the brain. Recently, we have shown that AUD is associated with changes in DNA methylation mechanisms. However, the role of DNA methylation in the regulation of neurosteroid biosynthesis and GABAergic neurotransmission in AUD patients remains under-investigated. Methods In a cohort of postmortem brains from 20 male controls and AUD patients, we investigated the expression of GABAAR subunits and neurosteroid biosynthetic enzymes and their regulation by DNA methylation mechanisms. Neurosteroid levels were quantified by gas chromatography-mass spectrometry. Results The α 2 subunit expression was reduced due to increased DNA methylation at the gene promoter region in the cerebellum of AUD patients, a brain area particularly sensitive to the effects of alcohol. Alcohol-induced alteration in GABAAR subunits was also observed in the prefrontal cortex. Neurosteroid biosynthesis was also affected with reduced cerebellar expression of the 18kDa translocator protein and 3α-hydroxysteroid dehydrogenase mRNAs. Notably, increased DNA methylation levels were observed at the promoter region of 3α-hydroxysteroid dehydrogenase. These changes were associated with markedly reduced levels of allopregnanolone and pregnanolone in the cerebellum. Conclusion Given the key role of neurosteroids in modulating the strength of GABAAR-mediated inhibition, our data suggest that alcohol-induced impairments in GABAergic neurotransmission might be profoundly impacted by reduced neurosteroid biosynthesis most likely via DNA hypermethylation.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Silvana C. E. Maas ◽  
Michelle M. J. Mens ◽  
Brigitte Kühnel ◽  
Joyce B. J. van Meurs ◽  
André G. Uitterlinden ◽  
...  

Abstract Background Tobacco smoking is a well-known modifiable risk factor for many chronic diseases, including cardiovascular disease (CVD). One of the proposed underlying mechanism linking smoking to disease is via epigenetic modifications, which could affect the expression of disease-associated genes. Here, we conducted a three-way association study to identify the relationship between smoking-related changes in DNA methylation and gene expression and their associations with cardio-metabolic traits. Results We selected 2549 CpG sites and 443 gene expression probes associated with current versus never smokers, from the largest epigenome-wide association study and transcriptome-wide association study to date. We examined three-way associations, including CpG versus gene expression, cardio-metabolic trait versus CpG, and cardio-metabolic trait versus gene expression, in the Rotterdam study. Subsequently, we replicated our findings in The Cooperative Health Research in the Region of Augsburg (KORA) study. After correction for multiple testing, we identified both cis- and trans-expression quantitative trait methylation (eQTM) associations in blood. Specifically, we found 1224 smoking-related CpGs associated with at least one of the 443 gene expression probes, and 200 smoking-related gene expression probes to be associated with at least one of the 2549 CpGs. Out of these, 109 CpGs and 27 genes were associated with at least one cardio-metabolic trait in the Rotterdam Study. We were able to replicate the associations with cardio-metabolic traits of 26 CpGs and 19 genes in the KORA study. Furthermore, we identified a three-way association of triglycerides with two CpGs and two genes (GZMA; CLDND1), and BMI with six CpGs and two genes (PID1; LRRN3). Finally, our results revealed the mediation effect of cg03636183 (F2RL3), cg06096336 (PSMD1), cg13708645 (KDM2B), and cg17287155 (AHRR) within the association between smoking and LRRN3 expression. Conclusions Our study indicates that smoking-related changes in DNA methylation and gene expression are associated with cardio-metabolic risk factors. These findings may provide additional insights into the molecular mechanisms linking smoking to the development of CVD.


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