Project description:The objective of The Center for Alcohol Research in Epigenetics (CARE) is to identify gene regulatory pathways in hippocampus that are altered in response to chronic ethanol administration and withdrawal.
Project description:The objective of The Center for Alcohol Research in Epigenetics (CARE) is to identify gene regulatory pathways in ventral tegmental area (VTA) that are altered in response to chronic ethanol administration and withdrawal.
Project description:While women are more vulnerable than men to many of the medical consequences of alcohol abuse, the role of sex in the response to ethanol is controversial. Neuroadaptive responses that result in the hyperexcitability associated with withdrawal from chronic ethanol likely reflect gene expression changes. We have examined both genders for the effects of withdrawal on brain gene expression using mice with divergent withdrawal severity that have been selectively bred from a genetically heterogeneous population. A total of 295 genes were identified as ethanol regulated from each gender of each selected line by microarray analyses. Hierarchical cluster analysis of the arrays revealed that the transcriptional response correlated with sex rather than with the selected withdrawal phenotype. Consistent with this, gene ontology category over-representation analysis identified cell death and DNA/RNA binding as targeted classes of genes in females, while in males, protein degradation, and calcium ion binding pathways weremore altered by alcohol. Examination of ethanol regulated genes and these distinct signaling pathways suggested enhanced neurotoxicity in females. Histopathological analysis of brain damage following ethanol withdrawal confirmed elevated cell death in female but not male mice. The sexually dimorphic response was observed irrespective of withdrawal phenotype. Combined, these results indicate a fundamentally distinct neuroadaptive response in females compared to males during chronic ethanol withdrawal and are consistent with observations that female alcoholics may be more vulnerable than males to ethanol-induced brain damage associated with alcohol abuse.
Project description:While women are more vulnerable than men to many of the medical consequences of alcohol abuse, the role of sex in the response to ethanol is controversial. Neuroadaptive responses that result in the hyperexcitability associated with withdrawal from chronic ethanol likely reflect gene expression changes. We have examined both genders for the effects of withdrawal on brain gene expression using mice with divergent withdrawal severity that have been selectively bred from a genetically heterogeneous population. A total of 295 genes were identified as ethanol regulated from each gender of each selected line by microarray analyses. Hierarchical cluster analysis of the arrays revealed that the transcriptional response correlated with sex rather than with the selected withdrawal phenotype. Consistent with this, gene ontology category over-representation analysis identified cell death and DNA/RNA binding as targeted classes of genes in females, while in males, protein degradation, and calcium ion binding pathways weremore altered by alcohol. Examination of ethanol regulated genes and these distinct signaling pathways suggested enhanced neurotoxicity in females. Histopathological analysis of brain damage following ethanol withdrawal confirmed elevated cell death in female but not male mice. The sexually dimorphic response was observed irrespective of withdrawal phenotype. Combined, these results indicate a fundamentally distinct neuroadaptive response in females compared to males during chronic ethanol withdrawal and are consistent with observations that female alcoholics may be more vulnerable than males to ethanol-induced brain damage associated with alcohol abuse. A total of 32 microarrays were run with 4 biological replicates per treatment, line, and sex. Selection replicates (i.e. WSP-1 and WSP-2) for each treatment, line, and sex were collapsed to improve statistical power (n=4) and to facilitate in the identification of phenotype related effects and exclude selection artifacts. For comparisons, EtOH regulation was determined by comparing 4 arrays from (for example) Male WSR EtOH treated versus 4 arrays from Male WSR Air treated arrays.
Project description:Cycles of heavy drinking and abstinence can lead to ethanol abuse disorder. We studied the effects of chronic intermittent ethanol exposure (CIE) over three weeks on neuroblastoma cells, using an ethanol concentration frequently attained in binge drinking (40 mM, 184 mg/dl). There were many changes in gene expression but most were small. CIE affected pathways instrumental in the development or plasticity of neurons, including axonal guidance, reelin signaling and synaptogenesis. Genes involved in dopamine and serotonin signaling were also affected. Changes in transporters and receptors could dampen both NMDA and norepinephrine transmissions. Decreased expression of the GABA transporter SLC6A11 could increase GABA transmission and has been associated with a switch from sweet drinking to ethanol consumption in rats. Ethanol increased stress responses such as unfolded protein response. TGF-β and NFκB signaling were increased. Most of the genes involved in cholesterol biosynthesis were decreased in expression. Withdrawal for 24 h after CIE caused most of the CIE-induced expression changes to move back toward unexposed levels.
Project description:Lasting behavioral and physiological changes such as abusive consumption, dependence, and withdrawal are characteristic features of alcohol use disorders (AUD). Mechanistically, persistent changes in gene expression are hypothesized to contribute to these brain adaptations leading to ethanol toxicity and abuse. Here we employed repeated chronic intermittent ethanol (CIE) exposure by vapor chamber as a mouse model to simulate the cycles of ethanol exposure and withdrawal commonly seen with AUD. This model has previously been shown to induce progressive ethanol consumption in rodents. Brain regional expression networks contributing to CIE-induced behavioral changes were identified by microarray analysis across five brain regions in the mesolimbic dopamine system and extended amygdala with tissue harvested from 0-120 hours following the last cycle of CIE. Weighted Gene Correlated Network Analysis (WGCNA) was used to identify gene networks over-represented for CIE-induced temporal expression changes across brain regions. Differential gene expression analysis of CIE vs. air-treated controls showed that long-lasting gene regulation occurred 5-days after the final cycle of ethanol exposure only in prefrontal cortex (PFC) and hippocampus. In the majority of brain-regions, however, ethanol regulated gene expression changes occurred only immediately following CIE or within the first 8-hours of removal from ethanol. Bioinformatics analysis of modules identified by WGCNA showed that neuroinflammatory responses were seen across multiple brain regions at early time-points, whereas co-expression modules related to neuroplasticity, chromatin remodeling, and neurodevelopment were seen at later time-points and in specific brain regions (PFC or HPC). In PFC a module containing Bdnf was identified as highly CIE responsive in a biphasic manner, with peak changes at 0 hours and 5 days following CIE, suggesting a possible role in mechanisms underlying long-term molecular and behavioral response to CIE. Strikingly, bioinformatics analysis of this network and several other modules identified Let-7 family microRNAs as potential regulators of gene expression changes induced by CIE. Our results suggest a complex temporal and regional pattern of widespread gene network responses involving neuroinflammatory and neuroplasticity related genes as contributing to physiological and behavioral responses to chronic ethanol. In particular, our identification of a potential role for Let-7 miRNAs and a Bdnf-related expression network in long-lasting expression changes after CIE may lead to future druggable gene target identification for novel intervention in AUD.
Project description:Corticotropin-releasing factor and its cognate type-1 receptor, a prominent brain stress system, is implicated in anxiety and alcohol use disorder (AUD). We tested the hypothesis that medial prefrontal cortex CRF1-expressing (mPFCCRF1+) neurons comprise a distinct population that exhibits neuroadaptations following withdrawal from chronic ethanol that underlie AUD- related behavior. We found that mPFCCRF1+ neurons comprise a glutamatergic population with distinct electrophysiological properties and regulate anxiety and conditioned rewarding effects of ethanol. To gain mechanistic insight into these electrophysiological adaptations, we sequenced the transcriptome of mPFCCRF1+ neurons and found that withdrawal leads to an increase in colony-stimulating factor 1 (CSF1) in this population. We found that selective overexpression of CSF1 in mPFCCRF1+ neurons is sufficient to decrease glutamate transmission, heighten anxiety, and abolish ethanol reinforcement, providing mechanistic insight into the observed mPFCCRF1+ synaptic adaptations in withdrawal that drive these behavioral phenotypes. Together, these findings highlight mPFCCRF1+ neurons as a critical site of enduring adaptations that may contribute to the persistent vulnerability to ethanol misuse in abstinence, and CSF1 as a novel target for therapeutic intervention for withdrawal-related negative affect.
Project description:Ethanol is the most common substance of abuse in the US, and abuse can lead to physical dependence, addiction, brain damage and premature death. The cycle of alcohol addiction has been described as a composite consisting of three stages: intoxication, withdrawal and craving/abstinence. As a complex brain disorder, there is evidence for both a genetic contribution to risk and sexually-dimorphic responses in alcoholism, but an overall understanding of the biological contributions and the neuroadaptive underpinnings of alcohol addiction is limited. Utilizing novel genetic animal models with highly divergent withdrawal severity, Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) selected lines of mice and by examining both sexes, the distinct or common contributions of response to alcohol genotype/phenotype and of sex to addiction stages over time were characterized. Transcriptional profiling was performed to identify neuroadaptive changes as a consequence of chronic intoxication in the medial prefrontal cortex (mPFC). Significant expression differences were identified for each line and tracked over a behaviorally-relevant time course that covered each stage of alcohol addiction; i.e., after chronic intoxication, during peak withdrawal, and after a defined period of abstinence. Females were more responsive to ethanol with higher fold expression differences. Data structure was analyzed by bioinformatics, which showed a strong effect of sex with high similarity of male vs. female expression profiles during chronic intoxication and at peak withdrawal irrespective of genetic background. However, during abstinence, striking differences were observed instead between the lines/phenotypes irrespective of sex. Because sex was the strongest influence on neuroadaptive changes overall, confirmation analysis compared males vs. females. Notably, results revealed distinct inflammatory signaling between males and females at peak withdrawal, with a pro-inflammatory inflammotoxic phenotype in females but in contrast overall suppression of immune signaling in males. Thus, the early response to chronic intoxication is strongly influenced by sex while pathways that are altered during a period of abstinence are dependent on genotype. Combined, these results suggest that each stage of the addiction cycle is influenced differentially by sex vs. genetic background and support the development of distinct translational targets for stage- and sex-specific therapies for the treatment of alcohol withdrawal and the maintenance of sobriety.
Project description:Ethanol is the most common substance of abuse in the US, and abuse can lead to physical dependence, addiction, brain damage and premature death. The cycle of alcohol addiction has been described as a composite consisting of three stages: intoxication, withdrawal and craving/abstinence. As a complex brain disorder, there is evidence for both a genetic contribution to risk and sexually-dimorphic responses in alcoholism, but an overall understanding of the biological contributions and the neuroadaptive underpinnings of alcohol addiction is limited. Utilizing novel genetic animal models with highly divergent withdrawal severity, Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) selected lines of mice and by examining both sexes, the distinct or common contributions of response to alcohol genotype/phenotype and of sex to addiction stages over time were characterized. Transcriptional profiling was performed to identify neuroadaptive changes as a consequence of chronic intoxication in the medial prefrontal cortex (mPFC). Significant expression differences were identified for each line and tracked over a behaviorally-relevant time course that covered each stage of alcohol addiction; i.e., after chronic intoxication, during peak withdrawal, and after a defined period of abstinence. Females were more responsive to ethanol with higher fold expression differences. Data structure was analyzed by bioinformatics, which showed a strong effect of sex with high similarity of male vs. female expression profiles during chronic intoxication and at peak withdrawal irrespective of genetic background. However, during abstinence, striking differences were observed instead between the lines/phenotypes irrespective of sex. Because sex was the strongest influence on neuroadaptive changes overall, confirmation analysis compared males vs. females. Notably, results revealed distinct inflammatory signaling between males and females at peak withdrawal, with a pro-inflammatory inflammotoxic phenotype in females but in contrast overall suppression of immune signaling in males. Thus, the early response to chronic intoxication is strongly influenced by sex while pathways that are altered during a period of abstinence are dependent on genotype. Combined, these results suggest that each stage of the addiction cycle is influenced differentially by sex vs. genetic background and support the development of distinct translational targets for stage- and sex-specific therapies for the treatment of alcohol withdrawal and the maintenance of sobriety. A total of 32 microarrays were run with 4 biological replicates per treatment, line, and sex. Selection replicates (i.e. WSP-1 and WSP-2) for each treatment, line, and sex were collapsed to improve statistical power (n=4) and to facilitate in the identification of phenotype related effects and exclude selection artifacts. For comparisons, EtOH regulation was determined by comparing 4 arrays from (for example) Male WSR EtOH treated versus 4 arrays from Male WSR Air treated arrays.