Project description:Purpose: Traditional whole-tissue sequencing approaches do not fully capture brain cell-type specific effects of chronic alcohol. Therefore, the purpose of this study was to identify the specific transcriptome alterations in astrocytes due to chronic alcohol. Methods: We performed RNA-sequencing on astrocytes isolated from the prefrontal cortex (PFC) of C57BL/6J mice following chronic every-other-day alcohol consumption. Results: Differential expression analysis revealed alcohol-induced gene expression changes unique to astrocytes that could not be identified using whole tissue homogenate analysis. Enrichment analysis revealed involvement of calcium-related signaling and regulation of extracellular matrix genes in the astrocyte response to alcohol abuse. Conclusion: Our study presents the first focused analysis on the astrocyte transcriptome following chronic alcohol consumption, provides a framework for studying the functional response of astrocytes to alcohol and the possible astrocyte-specific effects of alcohol. In addition, our data represents a novel resource for groups interested in biological functions of astrocytes in the adult mouse PFC.
Project description:Action of alcohol on synaptic mRNA in the amygdala of mice Chronic alcohol consumption induces changes in gene expression, causing persistent long-term neuro-adaptations and the remodeling of synaptic structures. These alcohol-induced synaptic changes may rely specifically on the local translation of mRNAs in the synaptic compartments of the cell. We profiled the transcriptome from synaptoneurosomes (SN) and paired total homogenates (TH) of amygdala to analyze the synaptic adaptations induced by chronic voluntary alcohol consumption in mice. In the SN both the number of alcohol-responsive mRNAs and the magnitude of fold-change were greater than in the TH. Accordingly, the SN detected many genes with coordinated patterns of expression producing a highly connected mRNA network in gene co-expression analysis. The greater sensitivity of the SN preparation allowed for improved cell-type specificity analysis, revealing an up-regulation of alcohol-responsive astrocytic and microglial modules that correlated with alcohol consumption. Alcohol was found to induce changes in the SN functionally important biological pathways, including long-term potentiation, long-term potentiation depression, glutamate pathway, neuro-immune, RNA-processing and translational machineries and provided overlap with changes seen in human alcoholic brain. Transposable elements were responsive to alcohol and found in the down-regulated neuronal mRNA module, which may underlie some of the coordinated gene expression changes associated with alcohol. We provide evidence that enrichment of synaptic components reveals a more intricate network of coordinated gene expression. Increased resolution captures the molecular effects of synaptic manipulations and provides an improved technique for identifying therapeutic targets for alcohol abuse. Synaptoneurosomes (SN) and Paired total homogenates (TH) were prepared from the same homogenate. 42 microarrays were used in total for the alcohol-control analysis (8 alcohol treated mice and 13 controls), 21 SN and 21 paired TH. 2 TH (control) samples were found outliers and were removed from the analysis. For the SN vs. TH analysis, the 2 TH samples found outliers were removed with the 2 paired SN samples.
Project description:Purpose: Alcohol abuse induces changes in microglia morphology and immune function, but whether microglia initiate or simply amplify the harmful effects of alcohol exposure is still a matter of debate. Here we determined microglia function in acute and voluntary drinking behaviors using a colony stimulating factor 1 receptor inhibitor (PLX5622) and 3’UTR biased-sequencing. Therefore, The purpose of this study was to provide insight regarding microglia depletion and voluntary alcohol consumption. Methods: We performed 3’UTR biased transcriptome sequencing (3’Tag-seq) on total homogenate isolated from the prefrontal cortex (PFC) of C57BL6/J mice following microglia depletion and chronic every-other-day alcohol consumption. Results: Differential expression analysis and WGCNA network analysis revealed that although many immune genes have been implicated in alcohol abuse, downregulation of microglia genes does not necessitate changes in alcohol intake. Finally, we show that microglia depletion and chronic alcohol result in compensatory upregulation of ethanol-responsive, reactive astrocyte genes, indicating astrocytes may play a critical role in regulation of these alcohol behaviors. Conclusion:Taken together our behavioral and transcriptional data indicate that microglia are not the primary effector cell responsible for regulation of acute and voluntary alcohol behaviors. In addition, our data represents a novel resource for groups interested in transcriptional effects of microglia depletion after alcohol consumption.
Project description:We investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice. We identified similar patterns of transcriptional changes in brain and liver among three different alcohol consumption tests and lipopolysaccharide injection. We also demonstrated distinct genomic consequences of different types of alcohol consumption. The microarray experiment was performed to compare gene expression changes induced by three separate paradigms of alcohol consumption and immune activation by lipopolysaccharide injection. The three tests of alcohol consumption were the continuous chronic two bottle choice (Chronic), two bottle choice available every other day (Chronic Intermittent) and limited access to one bottle of ethanol (Drinking in the Dark). All alcohol studies utilized 20% ethanol and each treatment group had it's own control group which received only water. The immune activation test consisted of 2 lipopolysaccharide injections (1 mg/kg i.p.) spaced one week apart, with animals being sacrificed one week after the last injection. Control animals received saline injections. All studies used female, adult mice.
Project description:Action of alcohol on synaptic mRNA in the amygdala of mice Chronic alcohol consumption induces changes in gene expression, causing persistent long-term neuro-adaptations and the remodeling of synaptic structures. These alcohol-induced synaptic changes may rely specifically on the local translation of mRNAs in the synaptic compartments of the cell. We profiled the transcriptome from synaptoneurosomes (SN) and paired total homogenates (TH) of amygdala to analyze the synaptic adaptations induced by chronic voluntary alcohol consumption in mice. In the SN both the number of alcohol-responsive mRNAs and the magnitude of fold-change were greater than in the TH. Accordingly, the SN detected many genes with coordinated patterns of expression producing a highly connected mRNA network in gene co-expression analysis. The greater sensitivity of the SN preparation allowed for improved cell-type specificity analysis, revealing an up-regulation of alcohol-responsive astrocytic and microglial modules that correlated with alcohol consumption. Alcohol was found to induce changes in the SN functionally important biological pathways, including long-term potentiation, long-term potentiation depression, glutamate pathway, neuro-immune, RNA-processing and translational machineries and provided overlap with changes seen in human alcoholic brain. Transposable elements were responsive to alcohol and found in the down-regulated neuronal mRNA module, which may underlie some of the coordinated gene expression changes associated with alcohol. We provide evidence that enrichment of synaptic components reveals a more intricate network of coordinated gene expression. Increased resolution captures the molecular effects of synaptic manipulations and provides an improved technique for identifying therapeutic targets for alcohol abuse. Local translation of mRNAs in the synapse plays a major role in synaptic structure and function. Chronic alcohol use causes persistent changes in synaptic mRNA expression, possibly mediated by microRNAs localized in the synapse. We profiled the transcriptome of synaptoneurosomes (SN) from the amygdala of mice chronically consuming 20% ethanol in a continuous two-bottle choice test to identify the microRNAs that target alcohol-induced mRNAs. SN are membrane vesicles containing pre- and post-synaptic compartments of neurons and astroglia and are a unique model for studying the synaptic transcriptome. We previously showed that chronic alcohol regulates mRNA expression in a coordinated manner. Here, we examine microRNAs and mRNAs from the same samples to define alcohol-responsive synaptic microRNAs and their predicted interactions with targeted mRNAs. We used a combination of unbiased bioinformatic methods (differential expression, correlation, co-expression, microRNA-mRNA target prediction, co-targeting and cell type specific analyses) to identify key alcohol-sensitive microRNAs. Bidirectional mRNA-microRNA prediction analysis showed that a subset of alcohol-responsive microRNAs were predicted to target many alcohol-responsive mRNAs. We found microRNAs-mRNAs with overlapping patterns of expression that correlated with the amount of alcohol consumed. Cell-type specific analysis revealed a significant number of the alcohol-responsive mRNAs and microRNAs that were unique to glutamate neurons and were highly predicted to target each other. Chronic alcohol appears to perturb the coordinated microRNA regulation of mRNAs in SN, a mechanism that may explain the aberrations in synaptic plasticity affecting the alcoholic brain.
Project description:We investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice. We identified similar patterns of transcriptional changes in brain and liver among three different alcohol consumption tests and lipopolysaccharide injection. We also demonstrated distinct genomic consequences of different types of alcohol consumption.