Project description:In order to elucidate the molecular mechanisms underlying individual variation in sensitivity to ethanol we profiled the prefrontal cortex transcriptomes of two inbred strains that exhibit divergent responses to acute ethanol, the C57BL6/J (B6) and DBA/2J (D2) strains, as well as 27 members of the BXD recombinant inbred panel, which was derived from a B6 x D2 cross. With this dataset we were able to identify several gene co-expression networks that were robustly altered by acute ethanol across the BXD panel. These ethanol-responsive gene-enriched networks were heavily populated by genes regulating synaptic transmission and neuroplasticity, and showed strong genetic linkage to discreet chromosomal loci. Network-based measurements of node importance identified several hub genes as established regulators of ethanol response phenotypes, while other hubs represent novel candidate modulators of ethanol responses.
Project description:In order to elucidate the molecular mechanisms underlying individual variation in sensitivity to ethanol we profiled the prefrontal cortex transcriptomes of two inbred strains that exhibit divergent responses to acute ethanol, the C57BL6/J (B6) and DBA/2J (D2) strains, as well as 27 members of the BXD recombinant inbred panel, which was derived from a B6 x D2 cross. With this dataset we were able to identify several gene co-expression networks that were robustly altered by acute ethanol across the BXD panel. These ethanol-responsive gene-enriched networks were heavily populated by genes regulating synaptic transmission and neuroplasticity, and showed strong genetic linkage to discreet chromosomal loci. Network-based measurements of node importance identified several hub genes as established regulators of ethanol response phenotypes, while other hubs represent novel candidate modulators of ethanol responses. Animals were injected intraperitoneally (IP) with saline or 1.8 g/kg of ethanol. As part of a parallel study of ethanol induced anxiolysis, all mice underwent behavioral testing that included 15 minutes of restraint in a 50 mL conical tube followed by 10 minutes in a light-dark chamber. Mice were killed by cervical dislocation four hours following IP injection. Immediately thereafter, brains were extracted and chilled for 1 minute in iced phosphate buffer before being microdissected into 8 constituent regions, including the medial prefrontal cortex. Samples were randomly assigned to batch groups prior to total RNA extraction, cRNA synthesis and hybridization. Each microarray represent a pooling of 4-5 animals.
Project description:Ethanol’s anxiolytic actions contribute to increased consumption and the development of Alcohol Use Disorder (AUD). Our laboratory previously identified genetic loci contributing to the anxiolytic-like properties of ethanol in BXD recombinant inbred mice, derived from C57BL/6J (B6) and DBA/2J (D2) progenitor strains. That work identified Ninein (Nin) as a candidate gene underlying ethanol’s acute anxiolytic-like properties in BXD mice. Nin has a complex exonic content with known alternative splicing events that alter cellular distribution of the NIN protein. We hypothesize that strain-specific differences in Nin alternative splicing contribute to changes in Nin gene expression and B6/D2 strain differences in ethanol anxiolysis. Using quantitative reverse-transcriptase PCR to target Nin alternative splicing, we identified isoform-specific exon expression differences between B6 and D2 mice in prefrontal cortex, nucleus accumbens and amygdala. We extended this analysis using deep RNA sequencing in B6 and D2 nucleus accumbens samples and that Nin expression was significantly higher in D2 mice. Furthermore, exon utilization and alternative splicing analyses identified 8 differentially utilized exons and significant exon-skipping events between the strains, including 3 novel splicing events in the 3’ end of the Nin gene that were specific to the D2 strain. Our studies provide the first in-depth analysis of Nin alternative splicing in brain and identify a potential genetic mechanism altering Nin expression between B6 and D2 mice, thus contributing to differences in the anxiolytic-like properties of ethanol between these strains. This work contributes to our understanding of genetic differences modulating ethanol actions on anxiety that may contribute to the risk for alcohol use disorder.
Project description:Animal models provide opportunity to study neurobiological aspects of human alcoholism. Changes in gene expression have been implicated in mediating brain function, including reward system and addiction. The current study aimed to identify novel genes that may underlie ethanol preference. Microarray analysis comparing gene expression in nucleus accumbens (NAc), hippocampus (HP) and prefrontal medial cortex (mPFC) was performed in two rat strains selected for extreme levels of ethanol preference - Warsaw High Preferring (WHP) and Warsaw Low Preferring (WLP). The identified candidate genes may underlie differential ethanol preference in rat model of alcoholism. This is analysis of 18 RNA samples, including 9 technical replicates. Two strains of rats selected for extreme levels of ethanol preference (low preferring WLP and high preferring WHP) were compared. Three brain areas (nucleus accumbens, prefrontal medial cortex and hippocampus) were studied. For each brain area, 6 RNA samples (including 3 technical replicates) were analyzed. Each RNA sample consist of of equal amounts of total RNA from 3 male rats. Comparisons: Nucleus accumbens of WHP vs. Nucleus accumbens of WLP; Prefrontal medial cortex of WHP vs. Prefrontal medial cortex of WLP; Hippocampus of WHP vs. Hippocampus of WLP. 3 biological replicates in each comparison.
Project description:Transcriptional study to investigate differences in prefrontal cortex and striatum of mice that consumed ethanol despite negative consequences, which resembles the compulsive aspect of alcohol addiction. The transcriptional analysis performed in the striatum and prefrontal cortex revealed genes and biological pathways differentially regulated specifically in animals of the group Inflexible Drinkers that could be involved with the loss of control over voluntary ethanol consumption (da Silva E Silva et al., 2016; de Paiva Lima et al., 2017).
Project description:We examined microRNA expression profiles in amygdala (AMY), nucleus accumbens (NAC) and prefrontal cortex (PFC) of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure.
Project description:We examined global gene expression profiles in amygdala (AMY), nucleus accumbens (NAC), prefrontal cortex (PFC) and Liver of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure.
Project description:In a previous study, we identified extensive natural variation in the response to acute ethanol treatment in three yeast strains: a lab strain derived from the commonly used S288c (DBY8268), vineyard isolate M22, and oak soil strain YPS163. Many expression differences persisted across several modules of co-regulated genes, implicating trans-acting systemic differences in ethanol sensing and/or response. To understand the genetic basis for these expression differences, we performed eQTL mapping analysis of the response to acute ethanol stress in ~100 F2 strains from two crosses: DBY8268x M22 and DBY8268 x YPS163.