Project description:To determine the transcriptomic changes elicited by drugs of abuse, zebrafish embryos were exposed to 10uM morphine from 5 hpf (hours post-fertilization) to 72 hpf. Embryos were euthanized and deep frozen with N2(l). RNA was extracted and an RNA-seq assay was performed with Illumina Platform
Project description:In summary, we characterized genomic signatures of response to drugs of abuse and we found positive correlations between the drug-induced expression and various behavioral effects. These signatures are formed by two dynamically inducible transcriptional networks: (1) CREB/SRF-dependent gene pattern that appears to be related to drug-induced neuronal activity, (2) the pattern of genes controlled at least in part via release of glucocorticoids and androgens that are associated with rewarding and harmful drug effects. The discovery of co-expressed networks of genes allowed for the identification of master-switch controlling factors involved in molecular response to the drugs. Finally, using the pharmacological tools we were able to dissect and inhibit particular gene expression patterns from genomic profile. Type: Drug response, Time-course, Gene expression profiling with Illumina Microarrays Keywords: Addiction, Drugs of abuse, Time-course, Immediate Early Genes, Glucocorticoid receptor dependent genes, Cocaine, Heroin, Nicotine, Ethanol, Morphine, Methamphetamine The microarray experiment was performed to analyze time-course of drug-induced transcriptional response in C57BL/6J mouse striatum. Six the most addictive and harming drugs of abuse (morphine 20 mg/kg, heroin 10 mg/kg, ethanol 2 g/kg, nicotine 1 mg/kg, methamphetamine 2 mg/kg or cocaine 25 mg/kg, i.p.) were selected for the comparison. Drug doses were previously reported as rewarding in mice and further tested in our laboratory. To analyze dynamics of early, intermediate and relatively late changes of mRNA abundance the experiment was performed in four time points (1, 2, 4 and 8h after drug administration). To exclude influence of drug injection and circadian rhythm on gene expression profile, control groups of saline treated and naïve animals were prepared for each time point. Design of the experiment assumed pooling of two animals per each array and using of three independent arrays per group. To provide appropriate balance in the whole dataset groups were equally divided between the array hybridization batches. 'Complete' normalized data and non-normalized data (containing control rows not represented in Platform GPL6105) are linked below as supplementary files.
Project description:In summary, we characterized genomic signatures of response to drugs of abuse and we found positive correlations between the drug-induced expression and various behavioral effects. These signatures are formed by two dynamically inducible transcriptional networks: (1) CREB/SRF-dependent gene pattern that appears to be related to drug-induced neuronal activity, (2) the pattern of genes controlled at least in part via release of glucocorticoids and androgens that are associated with rewarding and harmful drug effects. The discovery of co-expressed networks of genes allowed for the identification of master-switch controlling factors involved in molecular response to the drugs. Finally, using the pharmacological tools we were able to dissect and inhibit particular gene expression patterns from genomic profile. Type: Drug response, Time-course, Gene expression profiling with Illumina Microarrays Keywords: Addiction, Drugs of abuse, Time-course, Immediate Early Genes, Glucocorticoid receptor dependent genes, Cocaine, Heroin, Nicotine, Ethanol, Morphine, Methamphetamine
Project description:Substance use disorders (SUDs) are associated with disruptions in sleep and circadian rhythms that persist during abstinence and may contribute to relapse risk. Repeated use of substances such as psychostimulants and opioids may lead to significant alterations in molecular rhythms in the nucleus accumbens (NAc), a brain region central to reward and motivation. Previous studies have identified rhythm alterations in the transcriptome of the NAc and other brain regions following the administration of psychostimulants or opioids. However, little is known about the impact of substance use on the diurnal rhythms of the proteome in the NAc. We used liquid chromatography coupled to tandem mass spectrometry-based (LC-MS/MS) quantitative proteomics, along with a data-independent acquisition (DIA) analysis pipeline, to investigate the effects of cocaine or morphine administration on diurnal rhythms of proteome in the mouse NAc. Overall, our data reveals cocaine and morphine differentially alters diurnal rhythms of the proteome in the NAc, with largely independent differentially expressed proteins dependent on time-of-day. Pathways enriched from cocaine altered protein rhythms were primarily associated with glucocorticoid signaling and metabolism, whereas morphine was associated with neuroinflammation. Collectively, these findings are the first to characterize the diurnal regulation of the NAc proteome and demonstrate a novel relationship between phase-dependent regulation of protein expression and the differential effects of cocaine and morphine on the NAc proteome.
Project description:Histone acetylation and other modifications of the chromatin are important regulators of gene expression and, consequently, may contribute to drug-induced behaviors and neuroplasticity. Previous studies have shown that a reduction on histone deacetylase (HDAC) activity results on the enhancement of some psychostimulant-induced behaviors. In the present study, we extend those seminal findings by showing that the administration of the HDAC inhibitor sodium butyrate enhances morphine-induced locomotor sensitization and conditioned place preference. In contrast, this compound has no effects on the development of morphine tolerance and dependence. Similar effects were observed for cocaine and ethanol-induced behaviors. These behavioral changes were accompanied by a selective boosting of a component of the transcriptional program activated by chronic morphine administration that included circadian clock genes and other genes relevant in addictive behavior. Our results support an specific role for histone acetylation and the epigenetic modulation of transcription at a reduced number of biologically relevant loci on non-homeostatic, long lasting, drug-induced behavioral plasticity. To further investigate the molecular bases of sodium butyrate action on long-lasting behavioral responses to morphine, we screened for potential substrates of their interaction by performing a genome-wide comparison of the striatal transcriptome after chronic administration of morphine in the absence or presence of sodium butyrate. Striatal tissue was dissected from two months-old Swiss-Albino male mice subjected to behavioral sensitization. Behavioural sensitization: Locomotor sensitization induced by morphine was evaluated using a protocol divided into two phases: induction and challenge. The induction phase involved six trials on alternate days, one trial per day. On each one of these trials, mice received and injection of saline or sodium butyrate (300 mg/kg) immediatedly followed by a second injection of morphine (20 mg/kg). The challenge phases consisted of a single trial conducted 7 days after the last test of the induction phase. In this case, all animals received a single injection of morphine (20 mg/kg). Striatal RNA was extracted 1h after the morphine challenge in groups of four animals that received either saline (N=6) or morphine (N=3), or the sodium butyrate-morphine (N=3) co-treatment during the sensitization induction phase.
Project description:A hallmark of addiction is the ability of drugs of abuse to trigger relapse after periods of prolonged abstinence. Here, we describe a novel epigenetic mechanism whereby chronic cocaine exposure causes lasting chromatin and downstream transcriptional modifications in the nucleus accumbens (NAc), a critical brain region controlling motivation. We link prolonged withdrawal from cocaine to the depletion of the histone variant H2A.Z, coupled with increased genome accessibility and latent priming of gene transcription, in D1 dopamine receptor-expressing medium spiny neurons (D1 MSNs) that relate to aberrant gene expression upon drug relapse. The histone chaperone ANP32E removes H2A.Z from chromatin, and we demonstrate that D1 MSN-selective Anp32e knockdown prevents cocaine-induced H2A.Z depletion and blocks cocaine’s rewarding actions. By contrast, very different effects of cocaine exposure, withdrawal, and relapse were found for D2 MSNs. These findings establish histone variant exchange as an important mechanism and clinical target engaged by drugs of abuse to corrupt brain function and behavior.
Project description:Histone acetylation and other modifications of the chromatin are important regulators of gene expression and, consequently, may contribute to drug-induced behaviors and neuroplasticity. Previous studies have shown that a reduction on histone deacetylase (HDAC) activity results on the enhancement of some psychostimulant-induced behaviors. In the present study, we extend those seminal findings by showing that the administration of the HDAC inhibitor sodium butyrate enhances morphine-induced locomotor sensitization and conditioned place preference. In contrast, this compound has no effects on the development of morphine tolerance and dependence. Similar effects were observed for cocaine and ethanol-induced behaviors. These behavioral changes were accompanied by a selective boosting of a component of the transcriptional program activated by chronic morphine administration that included circadian clock genes and other genes relevant in addictive behavior. Our results support an specific role for histone acetylation and the epigenetic modulation of transcription at a reduced number of biologically relevant loci on non-homeostatic, long lasting, drug-induced behavioral plasticity. To further investigate the molecular bases of sodium butyrate action on long-lasting behavioral responses to morphine, we screened for potential substrates of their interaction by performing a genome-wide comparison of the striatal transcriptome after chronic administration of morphine in the absence or presence of sodium butyrate.
Project description:SH-SY5Y, neuroblastoma cells, were exposed to nicotine for 10, 60, and 90 minutes or cocaine for 5, 20, 40, and 60 minutes. Drugs of abuse modify behavior by altering gene expression in the brain. Gene expression can be regulated by changes in DNA methylation as well as by histone modifications, which alter chromatin structure, DNA compaction and DNA accessibility. In order to better understand the molecular mechanisms directing drug-induced changes in chromatin structure, we examined DNA-nucleosome interactions within promoter regions of 858 genes in human neuroblastoma cells (SH-SY5Y) exposed to nicotine or cocaine. Widespread, drug- and time-resolved repositioning of nucleosomes was identified at the transcription start site and promoter region of multiple genes. Nicotine and cocaine produced unique and shared changes in terms of the numbers and types of genes affected, as well as repositioning of nucleosomes at sites which could increase or decrease the probability of gene expression based on DNA accessibility. Half of the drug-induced nucleosome positions approximated a theoretical model of nucleosome occupancy based on physical and chemical characteristics of the DNA sequence, whereas the basal or drug-naive positions were generally DNA sequence independent. Thus we suggest that nucleosome repositioning represents an initial dynamic genome-wide alteration of the transcriptional landscape preceding more selective downstream transcriptional reprogramming, which ultimately characterizes the cell- and tissue-specific responses to drugs of abuse. SH-SY5Y, neuroblastoma cells, were exposed to nicotine for 10, 60, and 90 minutes or cocaine for 5, 20, 40, and 60 minutes. Two independently grown biological replicates for each time point and condition, and two controls were processed.
Project description:A hallmark of addiction is the ability of drugs of abuse to trigger relapse after periods of prolonged abstinence. Here, we describe a novel epigenetic mechanism whereby chronic cocaine exposure causes lasting chromatin and downstream transcriptional modifications in the nucleus accumbens (NAc), a critical brain region controlling motivation. We link prolonged withdrawal from cocaine to the depletion of the histone variant H2A.Z, coupled with increased genome accessibility and latent priming of gene transcription, in D1 dopamine receptor-expressing medium spiny neurons (D1 MSNs) that relate to aberrant gene expression upon drug relapse. The histone chaperone ANP32E removes H2A.Z from chromatin, and we demonstrate that D1 MSN-selective Anp32e knockdown prevents cocaine-induced H2A.Z depletion and blocks cocaine’s rewarding actions. By contrast, very different effects of cocaine exposure, withdrawal, and relapse were found for D2 MSNs. These findings establish histone variant exchange as an important mechanism and clinical target engaged by drugs of abuse to corrupt brain function and behavior.
Project description:Maintenance of the drug-addicted state involves changes in gene expression in different neuronal cell types and neural circuits. Midbrain dopamine neurons in particular mediate numerous responses to drugs of abuse. Long noncoding RNAs (lncRNAs) regulate CNS gene expression through a variety of mechanisms, but very little is known about their role in drug abuse. The proportion of lncRNAs that are primate-specific provides a strong rationale for their study in human drug abusers. We examined the profile of lncRNA expression in postmortem human midbrain specimens from chronic cocaine abusers and well-matched control subjects (n=11 subject pairs) using a custom lncRNA microarray. Differential expression was validated by quantitative PCR, and cellular localization investigated by in situ hybridization histochemistry.A profile of lncRNAs significantly dysregulated in chronic cocaine abusers was determined. LncRNAs with dopamine cell-specific expression, differential subcellular distribution, covariance with protein-coding genes, and tissue-specific drug-responsiveness were identified. Dysregulation of midbrain lncRNA expression may reflect pathophysiological processes associated with chronic cocaine abuse. LncRNAs may be central mediators of cellular responses to drug abuse. cRNAs were generated from postmortem human midbrain specimens from chronic cocaine abusers and well-matched control subjects and hybridized to a custom Agilent 4 x 44,000-feature high-density oligonucleotide microarray platform using 60-mer probes. Cocaine control pairs were run together in a dye-flip two-color design, meaning each sample was run in quadruplicate, twice with each dye (Alexa-647 and Alexa-555; Invitrogen, Carlsbad, CA). Microarray slides were scanned with the default Agilent protocol and the intensity of fluorescence between dyes was normalized using a Loess correction. There are 7 probes per gene. Data across all cases and quadruplicates were quantile-normalized.