Project description:Moderate alcohol consumption during pregnancy can result in a heterogeneous range of neurobehavioural and cognitive effects, termed fetal alcohol spectrum disorders (FASD). We have developed a mouse moder of FASD that involves moderate ethanol exposure throughout gestation achieved by voluntary maternal consumption. This model results in phenotypes relevant to FASD. Since ethanol is known to directly affect the expression of genes in the developing brain leading to abnormal cell death, changes to cell proliferation, migration, and differentiation, and potential changes to epigenetic patterning, we hypothesize that this leaves a long-term footprint on the adult brain. However, the long-term effects of prenatal ethanol exposure on brain gene expression, when behavioural phenotypes are apparent, are unclear. We used two independent microarray experiments and focused on the genes identified by both to evaluate the genome-wide alterations to the adult brain transcriptome caused by prenatal ethanol exposure via moderate maternal drinking.
Project description:Moderate alcohol exposure during pregnancy can result in a heterogeneous range of neurobehavioural and cognitive effects, termed fetal alcohol spectrum disorders (FASD). We have developed a mouse model of FASD that involves moderate ethanol exposure throughout gestation achieved by voluntary maternal consumption. This model results in phenotypes relevant to FASD. Since ethanol is known to directly affect the expression of genes in the developing brain leading to abnormal cell death, changes to cell proliferation, migration, and differentiation, and potential changes to epigenetic patterning, we hypothesize that this leaves a long-term footprint on the adult brain. However, the long-term effects of prenatal ethanol exposure on brain gene expression, when behavioural phenotypes are apparent, are unclear. We used a microarray experiment and focused on the genes identified by both to evaluate the genome-wide alterations to the adult brain transcriptome caused by prenatal ethanol exposure.
Project description:Moderate alcohol consumption during pregnancy can result in a heterogeneous range of neurobehavioural and cognitive effects, termed fetal alcohol spectrum disorders (FASD). We have developed a mouse moder of FASD that involves moderate ethanol exposure throughout gestation achieved by voluntary maternal consumption. This model results in phenotypes relevant to FASD. Since ethanol is known to directly affect the expression of genes in the developing brain leading to abnormal cell death, changes to cell proliferation, migration, and differentiation, and potential changes to epigenetic patterning, we hypothesize that this leaves a long-term footprint on the adult brain. However, the long-term effects of prenatal ethanol exposure on brain gene expression, when behavioural phenotypes are apparent, are unclear. We used two independent microarray experiments and focused on the genes identified by both to evaluate the genome-wide alterations to the adult brain transcriptome caused by prenatal ethanol exposure via moderate maternal drinking. To generate samples, two independent groups of female C57BL/6J mice were given access to 10% ethanol in water or water only. Control females had access to water only. Females were mated and continued to drink from gestational day 0 to pup postnatal day 10. Whole brain RNA from adult (postnatal day 70) male ethanol-exposed offspring was extracted. For experiment 1, RNA samples from three mice were pooled to reduce litter effects and the pooled samples were hybridized on Affymetrix arrays (2 control and 2 ethanol chips, total n=12 mice). For experiment 2, RNA from two mice were pooled per chip and three arrays per treatment were used (3 control, 3 ethanol, total n=12 mice).
Project description:Moderate alcohol exposure during pregnancy can result in a heterogeneous range of neurobehavioural and cognitive effects, termed fetal alcohol spectrum disorders (FASD). We have developed a mouse model of FASD that involves moderate ethanol exposure throughout gestation achieved by voluntary maternal consumption. This model results in phenotypes relevant to FASD. Since ethanol is known to directly affect the expression of genes in the developing brain leading to abnormal cell death, changes to cell proliferation, migration, and differentiation, and potential changes to epigenetic patterning, we hypothesize that this leaves a long-term footprint on the adult brain. However, the long-term effects of prenatal ethanol exposure on brain gene expression, when behavioural phenotypes are apparent, are unclear. We used a microarray experiment and focused on the genes identified by both to evaluate the genome-wide alterations to the adult brain transcriptome caused by prenatal ethanol exposure. To generate samples, female C57BL/6J mice were given ethanol injections (2.5g/kg of ethanol in saline) twice on gestational days 8 and 11 to produce acute ethanol exposure effects. Control females were injected with the same volume of saline. Females were mated. Whole brain RNA from adult (postnatal day 70) male ethanol-exposed offspring was extracted. RNA samples from three mice were pooled to reduce litter effects and the pooled samples were hybridized on Affymetrix arrays (2 control and 2 ethanol chips, total n=12 mice).
Project description:This is the first description of the effects of chronic ethanol consumption on the brain transcriptome in a non-human primate (rhesus macaque). Thirty male animals self-administered ethanol on a daily basis for over 12 months. Gene expression was measured with RNA-Seq in the central nucleus of the amygdala (CeA). Genes negatively correlated with consumption were enriched in functional annotations associated with translation and included clusters of ribosomal and mitochondrial ribosomal proteins. Genes positively correlated with consumption were enriched in membrane annotations including neuron and synapse part. Genes in the latter category included Ctnna2, Shank1, Vamp2, and Syn1. Gene-level expression data were clustered using the Weighted Gene Coexpression Network Analysis (WGCNA) algorithm to identify hub nodes affected by excessive consumption. Key hubs included Nf1, Nkain2, Tmem108 and Penk. The data were also analyzed for alternative exon usage (Iancu et al., 2015). Additional translation and membrane related genes affected by excessive consumption were detected. These included Grm2, Dpysl2 and Kcnc4. Overall, the data illustrate that the effects of excessive ethanol consumption are broad, consistent with the observation that ethanol affects the expression of numerous hub genes.
Project description:Persistent changes in brain gene expression are hypothesized to underlie thealtered neural signaling producing abusive consumption in AUD. To identify brain regional gene expression networks contributing to progressive ethanol consumption, we performed microarray and scale-free network analysis of expression responses in a C57BL/6J mouse model utilizing chronic intermittent ethanol by vapor chamber (CIE) in combination with limited access oral ethanol consumption. The interaction of CIE and oral consumption was studied with Affymetrix microarrays. Gene expression was studied in medial prefrontal cortex, nucleus accumbens, hippocampus, bed nucleus of the stria terminalis, and central nucleus of the amygdala. Brain region expression networks were analyzed for ethanol-responsive gene expression, correlation with ethanol consumption and functional content using extensive bioinformatics studies.
Project description:Introduction: Though heavy alcohol drinking has been well characterized as causing a variety of injuries, recent epidemiological evidence in humans suggests moderate consumption may provide beneficial effects. For example, there exists a J- or U-shaped relationship between the level of alcohol intake and cardiovascular disease risk. We investigated the underlying mechanisms of these positive consequences by identifying which genes are responsive to moderate alcohol intake in the liver, the primary site for alcohol metabolism. Methods: Twelve female, inbred, alcohol-preferring (iP10a) rats were split equally between chronic water exposure and voluntary chronic ethanol exposure. Hepatic cholesterol and triglyceride levels were analyzed both histologically and biochemically. Hepatic transcriptomes were paired-end sequenced on the Illumina HiScanSQ system. Reads were analyzed and mapped using CLCbio Genomics Workbench 4.9. We confirmed altered expression of a subset of genes using TaqMan-based qRT-PCR. To quantify DNA methylation, we first digested DNA with methylation sensitive restriction enzymes and then performed qPCR using TaqMan assays surrounding the digest sites. Calculating M-NM-^TCt between a mock digest and digest determines the percent methylation in that locus. Results: Voluntary alcohol consumption in iP10a rats modeled moderate consumption in humans. These levels did not result in intrahepatic fat accumulation. Sequencing produced ~1.2 Gb of sequence per sample, and 65% of reads mapped uniquely. Using a FDR corrected p value of 0.05 we found 250 altered transcripts. Ontology analysis of genes with a fold change M-bM-^IM-%1.3 identified many cholesterol synthesis genes and cytoskeleton subunit genes, all of which were down-regulated. Of the 28 genes reanalyzed by qRT-PCR, altered expression was confirmed in 24 genes including the majority of the cholesterol synthesis and cytoskeleton subunit genes. Lastly, we profiled methylation throughout the promoter and gene body of four genes elicited in the RNA-Seq experiment. We found that alcohol caused demethylation at all loci; however this loss happened in a site-specific, tightly regulated manner. Conclusion: Voluntary consumption in the iP10a animals models moderate consumption in humans, does not produce intrahepatic fat accumulation, and causes down-regulation of a majority of cholesterol synthesis genes. Moderate alcohol also results in a tightly-regulated demethylation effect. Our results explain, at least in part, the J- or U-shaped relationship between level of alcohol intake and cardiovascular disease risk. We sequenced 12 female iP10a rat hepatic transcriptomes providing 6 biological replicates for water control and 6 for ethanol treatment.
Project description:Background Maternal consumption of alcohol during pregnancy is associated with a range of physical, cognitive and behavioural outcomes in the offspring which are collectively called fetal alcohol spectrum disorders. We and others have proposed that epigenetic modifications, such as DNA methylation and post-translational histone modifications, mediate the effects of prenatal alcohol exposure on gene expression and, ultimately, phenotype. Here we use an inbred C57BL/6J mouse model of early gestational ethanol exposure equivalent, developmentally, to the first 3-4 weeks of pregnancy in humans to examine the long-term effects on gene expression and epigenetic state in the hippocampus. Results Gene expression analysis in the hippocampus revealed sex- and age-specific up-regulation of solute carrier family 17 member 6 (Slc17a6), which encodes vesicular glutamate transporter 2 (VGLUT2). Transcriptional up-regulation correlated with decreased DNA methylation and enrichment of histone H3 lysine 4 trimethylation, an active chromatin mark, at the Slc17a6 promoter. In contrast to Slc17a6 mRNA levels, hippocampal VGLUT2 protein levels were significantly decreased in adult ethanol-exposed offspring, suggesting an additional level of post-transcriptional control. MicroRNA expression profiling in the hippocampus identified four ethanol-sensitive microRNAs, of which miR-467b-5p was predicted to target Slc17a6. In vitro reporter assays showed that miR-467b-5p specifically interacted with the 3’ UTR of Slc17a6, suggesting that it contributes to the reduction of hippocampal VGLUT2 in vivo. A significant correlation between microRNA expression in the hippocampus and serum of ethanol-exposed offspring was also observed. Conclusions Prenatal ethanol exposure has complex transcriptional and post-transcriptional effects on Slc17a6 (VGLUT2) expression in the mouse hippocampus. These effects are observed following a relatively moderate exposure that is restricted to early pregnancy, modelling human consumption of alcohol before pregnancy is confirmed, and are only apparent in male offspring in adulthood. We propose that altered epigenetic and microRNA-mediated regulation of glutamate neurotransmission in the hippocampus contributes to the cognitive and behavioural phenotypes observed in fetal alcohol spectrum disorders. Our findings also support the idea that circulating microRNAs could be used as biomarkers of early gestational ethanol exposure and/or hippocampal dysfunction.