Neurogranin regulates alcohol sensitivity in the brain
Ontology highlight
ABSTRACT: Ng null mice demonstrated increased alcohol sensitivity. Therefore, we run label-free proteomics for mouse brain tissue after alcohol injection.
Project description:Alcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance. We performed artificial selection for alcohol sensitivity for 25 generations and created duplicate selection lines that are either highly sensitive or resistant to ethanol exposure along with unselected control lines. We used whole genome expression analysis to identify 1,678 probe sets with different expression levels between the divergent lines, pooled across replicates, at a false discovery rate of q < 0.001. We assessed to what extent genes with altered transcriptional regulation might be causally associated with ethanol sensitivity by measuring alcohol sensitivity of 37 co-isogenic P-element insertional mutations in 35 candidate genes, and found that 32 of these mutants differed in sensitivity to ethanol exposure from their co-isogenic controls. Furthermore, 23 of these novel genes have human orthologues. Combining whole genome expression profiling with selection for genetically divergent lines is an effective approach for identifying candidate genes that affect complex traits, such as alcohol sensitivity. Because of evolutionary conservation of function, it is likely that human orthologues of genes affecting alcohol sensitivity in Drosophila may contribute to alcohol-associated phenotypes in humans. Keywords: artificial selection, whole genome expression profiling
Project description:Alcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance. We performed artificial selection for alcohol sensitivity for 25 generations and created duplicate selection lines that are either highly sensitive or resistant to ethanol exposure along with unselected control lines. We used whole genome expression analysis to identify 1,678 probe sets with different expression levels between the divergent lines, pooled across replicates, at a false discovery rate of q < 0.001. We assessed to what extent genes with altered transcriptional regulation might be causally associated with ethanol sensitivity by measuring alcohol sensitivity of 37 co-isogenic P-element insertional mutations in 35 candidate genes, and found that 32 of these mutants differed in sensitivity to ethanol exposure from their co-isogenic controls. Furthermore, 23 of these novel genes have human orthologues. Combining whole genome expression profiling with selection for genetically divergent lines is an effective approach for identifying candidate genes that affect complex traits, such as alcohol sensitivity. Because of evolutionary conservation of function, it is likely that human orthologues of genes affecting alcohol sensitivity in Drosophila may contribute to alcohol-associated phenotypes in humans. Experiment Overall Design: Starting with flies from Raleigh natural population (see material and methods) we performed artificial selection for alcohol sensitivity for 35 generation. In each generations we scored 60 males and females, separately, from each line (resistant, sensitive, and control)using inebriometer, and the 20 highest-scoring flies from the resistant lines and the 20 lowest-scoring flies from the sensitive lines were selected as parents for the next generation. Control line flies were scored each generation and 20 random flies were used as parents. Experiment Overall Design: At generation 25, two replicates of 15 three-five day old virgin males and females were collected from each selection line. Total RNA was extracted from the 24 samples . Biotinylated cRNA probes were hybridized to high density oligonucleotide microarrays (Affymetrix, Inc. Drosophila GeneChip 2.0) and visualized with a streptavidin-phycoerythrin conjugate, as described in the Affymetrix GeneChip Expression Analysis Technical Manual (2000), using internal references for quantification. The quantitative estimate of expression of each probe set is the Signal (Sig) metric, as described in the Affymetrix Microarray Suite, Version 5.0.
Project description:In the adult brain, epigenetic control of gene expression has important roles in the processing of neural activity. Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, implicating specific metabolic factors in neural functions that drive behavior. In neurons, histone acetylation is dependent on the metabolite acetyl-CoA that is produced from acetate by chromatin-bound ACSS21. Here, using in vivo stable isotope labeling in mouse, we show that alcohol metabolism rapidly fuels histone acetylation in the brain by direct deposition of alcohol-derived acetyl groups onto histones in an ACSS2-dependent manner. A similar induction was observed with heavy labeled acetate injection in vivo. Injection of labeled alcohol into a pregnant mouse results in incorporation of labeled acetyl groups into gestating fetal brains, indicating that the acetate passes through the placenta. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced learning and memory-related transcriptional programs that were sensitive to ACSS2 inhibition. Strikingly, alcohol-related associative learning requires ACSS2 in vivo. These findings establish a novel and direct link between alcohol metabolism and neuronal ACSS2-dependent histone acetylation in the brain, providing evidence that dynamic acetate release from liver metabolism may travel to the brain for direct epigenetic regulation in neurons.
Project description:In the adult brain, epigenetic control of gene expression has important roles in the processing of neural activity. Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, implicating specific metabolic factors in neural functions that drive behavior. In neurons, histone acetylation is dependent on the metabolite acetyl-CoA that is produced from acetate by chromatin-bound ACSS21. Here, using in vivo stable isotope labeling in mouse, we show that alcohol metabolism rapidly fuels histone acetylation in the brain by direct deposition of alcohol-derived acetyl groups onto histones in an ACSS2-dependent manner. A similar induction was observed with heavy labeled acetate injection in vivo. Injection of labeled alcohol into a pregnant mouse results in incorporation of labeled acetyl groups into gestating fetal brains, indicating that the acetate passes through the placenta. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced learning and memory-related transcriptional programs that were sensitive to ACSS2 inhibition. Strikingly, alcohol-related associative learning requires ACSS2 in vivo. These findings establish a novel and direct link between alcohol metabolism and neuronal ACSS2-dependent histone acetylation in the brain, providing evidence that dynamic acetate release from liver metabolism may travel to the brain for direct epigenetic regulation in neurons.
Project description:In the adult brain, epigenetic control of gene expression has important roles in the processing of neural activity. Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, implicating specific metabolic factors in neural functions that drive behavior. In neurons, histone acetylation is dependent on the metabolite acetyl-CoA that is produced from acetate by chromatin-bound ACSS21. Here, using in vivo stable isotope labeling in mouse, we show that alcohol metabolism rapidly fuels histone acetylation in the brain by direct deposition of alcohol-derived acetyl groups onto histones in an ACSS2-dependent manner. A similar induction was observed with heavy labeled acetate injection in vivo. Injection of labeled alcohol into a pregnant mouse results in incorporation of labeled acetyl groups into gestating fetal brains, indicating that the acetate passes through the placenta. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced learning and memory-related transcriptional programs that were sensitive to ACSS2 inhibition. Strikingly, alcohol-related associative learning requires ACSS2 in vivo. These findings establish a novel and direct link between alcohol metabolism and neuronal ACSS2-dependent histone acetylation in the brain, providing evidence that dynamic acetate release from liver metabolism may travel to the brain for direct epigenetic regulation in neurons.
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:The National Institute on Alcohol Abuse and Alcoholism has estimated that approximately 14 million people in the United States suffer from alcoholism. Alcohol sensitivity, the development of tolerance to alcohol and susceptibility to addiction vary in the population. Whereas environmental factors, such as stress and social experience, contribute to individual variation in sensitivity to chronic alcohol consumption, genetic factors have also been implicated. However, genetic polymorphisms that predispose to alcoholism remain largely unknown due to extensive genetic and environmental variation in human populations. Drosophila, however, allows studies on genetically identical individuals in controlled environments. Although addiction to alcohol has not been demonstrated in Drosophila, flies show responses to alcohol exposure that resemble human intoxication, including hyperactivity, loss of postural control, sedation, and exposure-dependent development of tolerance. We assessed whole-genome transcriptional responses following alcohol exposure and demonstrate immediate down-regulation of olfactory sensitivity and, concomitant with development of tolerance, altered transcription of enzymes associated with fatty acid biosynthesis. Our results identify key enzymes in conserved metabolic pathways that may contribute to human alcohol sensitivity. Keywords: Drosophila, model system, alcohol sensitivity, tolerance
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.
Project description:The National Institute on Alcohol Abuse and Alcoholism has estimated that approximately 14 million people in the United States suffer from alcoholism. Alcohol sensitivity, the development of tolerance to alcohol and susceptibility to addiction vary in the population. Whereas environmental factors, such as stress and social experience, contribute to individual variation in sensitivity to chronic alcohol consumption, genetic factors have also been implicated. However, genetic polymorphisms that predispose to alcoholism remain largely unknown due to extensive genetic and environmental variation in human populations. Drosophila, however, allows studies on genetically identical individuals in controlled environments. Although addiction to alcohol has not been demonstrated in Drosophila, flies show responses to alcohol exposure that resemble human intoxication, including hyperactivity, loss of postural control, sedation, and exposure-dependent development of tolerance. We assessed whole-genome transcriptional responses following alcohol exposure and demonstrate immediate down-regulation of olfactory sensitivity and, concomitant with development of tolerance, altered transcription of enzymes associated with fatty acid biosynthesis. Our results identify key enzymes in conserved metabolic pathways that may contribute to human alcohol sensitivity. Experiment Overall Design: Alcohol sensitivity in Drosophila melanogaster can be quantified in an inebriometer. The elution time from the column is used as a measure of sensitivity to alcohol intoxication. Overall design: We collected 3-5 day old Canton S flies either without exposure to ethanol (control group), immediately after passage through the inebriometer, or from a population that had developed tolerance 2h after the initial ethanol exposure.
Project description:Background and Purpose: Alcohol use disorder (AUD) is a serious public health issue and affects the lives of numerous people. Previous studies have shown a link between nicotinic acetylcholine receptors (nAChR) and alcohol addiction. However, the role of α6β2* nAChR in alcohol addiction remains obscure and whether α6β2* nAChR can be used as a potential drug target for alcohol withdrawal need to be studied. Methods: Zebrafish (Danio rerio) were exposed to 0.2% alcohol for 14 days followed by 7 days of repeated withdrawal and then retro-orbitally injected with α-conotoxin TxIB (a selective α6β2* nAChR antagonist). RNA-sequencing (RNA-seq) and subsequent bioinformatics analysis were applied to explore the potential network regulation by blocking α6β2* nAChR using TxIB after alcohol withdrawal. Results: RNA sequencing of zebrafish brain indicated a total of 657 genes showed aberrant expression and among which 225 were reversed after TxIB injection. These reversed genes were significantly enriched in cardiac muscle contraction and calcium signaling pathways and the gene expression profile was further validated by RT-PCR. Conclusion: Our finding suggests α6β2* nAChR antagonists have the potential to modulate alcohol withdrawal.