Cocaine Regulates MEF2 to Control Synaptic and Behavioral Plasticity
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE11939 | GEO | 2008/08/24
SECONDARY ACCESSION(S): PRJNA105793
REPOSITORIES: GEO
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Project description:Repeated exposure to cocaine causes sensitized behavioral responses and increased dendritic spines on medium spiny neurons of the nucleus accumbens (NAc). We find that cocaine regulates myocyte enhancer factor 2 (MEF2) transcription factors to control these two processes in vivo. Cocaine suppresses striatal MEF2 activity in part through a novel mechanism involving cAMP, the regulator of calmodulin signaling (RCS), and calcineurin. We show that reducing MEF2 activity in the NAc in vivo is required for the cocaine-induced increases in dendritic spine density. Surprisingly, we find that increasing MEF2 activity in the NAc, which blocks the cocaine-induced increase in dendritic spine density, enhances sensitized behavioral responses to cocaine. Together, our findings implicate MEF2 as a key regulator of structural synapse plasticity and sensitized responses to cocaine, and suggest that reducing MEF2 activity (and increasing spine density) in NAc may be a compensatory mechanism to limit long-lasting maladaptive behavioral responses to cocaine. Mice were treated for 7 days with daily injections of cocaine (20 mg/kg) and sacrificed 24 hrs later. Chromatin from bilateral punches of NAc was immunoprecipitated with an antibody against MEF2A as described previously with minor modifications (Renthal et al., 2007). Chromatin was sonicated to an average of ~500 bp and immunoprepitated with antibody against MEF2A (Santa Cruz, sc-313) or an IgG control (Upstate/Millipore). Antibody-bound chromatin was precipitated using Protein A beads from Upstate (06-157), which were washed with low salt, high salt, and LiCl buffers to remove non-specific DNA binding. Eluted chromatin was reverse-crosslinked at 65oC in the presence of proteinase K and EDTA. DNA was purified by chloroform extraction/ethanol precipitation and the enrichment of specific promoters was amplified by ligation-mediated PCR for genome-wide analysis (Sikder et al., 2006). Amplified DNA was then labeled with Cy3 (input-enriched) or Cy5 (MEF2-enriched) and hybridized to Nimblegen (Madison, WI) MM8 mouse promoter arrays. Bilateral nucleus accumbens from eight mice were pooled for microarray analysis.
2008-08-24 | E-GEOD-11939 | biostudies-arrayexpress
Project description:Cocaine-induced alterations in gene expression cause changes in neuronal morphology and behavior that may underlie cocaine addiction. We identified an essential role for histone 3 lysine 9 (H3K9) dimethylation and the lysine dimethyltransferase G9a in cocaine-induced structural and behavioral plasticity. Repeated cocaine administration reduced global levels of H3K9 dimethylation in the nucleus accumbens. This reduction in histone methylation was mediated through the repression of G9a in this brain region. To identify whether changes in H3K9me2 correlated with genome-wide alterations in gene expression in the NAc, we employed microarray analyses to examine gene expression profiles induced by a challenge dose of cocaine in animals with or without a history of prior cocaine exposure. Animals that had received repeated cocaine displayed dramatically increased gene expression 1 hour after a cocaine challenge in comparison to acutely treated animals. This increased gene expression still occurred in response to a cocaine challenge given after 1 week of withdrawal from repeated cocaine. These data suggest that repeated, but not acute, cocaine exposure results in persistent sensitized genomic responses to a cocaine challenge, indicating that sensitized behavioral responses to repeated cocaine are likely the result of G9a-dependent alterations in global transcriptional responses to cocaine.
2009-10-28 | GSE18751 | GEO
Project description:Many of the long-term effects of cocaine on the brain's reward circuitry have been shown to be mediated by alterations in gene expression. Several chromatin modifications, including histone acetylation and methylation, have been implicated in this regulation, but the effect of other histone modifications remains poorly understood. Poly(ADP-ribose) polymerase-1 (PARP-1), a ubiquitous and abundant nuclear protein, catalyzes the synthesis of a negatively charged polymer called poly(ADP-ribose) or PAR on histones and other substrate proteins and forms transcriptional regulatory complexes with several other chromatin proteins. Here, we identify an essential role for PARP-1 in cocaine-induced molecular, neural, and behavioral plasticity. Repeated cocaine administration, including self-administration, increased global levels of PARP-1 and its mark PAR in mouse nucleus accumbens (NAc), a key brain reward region. Using PARP-1 inhibitors and viral-mediated gene transfer, we established that PARP-1induction in NAc mediates enhanced behavioral responses to cocaine, including increased self-administration of the drug. Using chromatin immunoprecipitation sequencing, we demonstrated a global, genome-wide enrichment of PARP-1 in NAc of cocaine-exposed mice and identified several PARP-1 target genes that could contribute to the lasting effects of cocaine. Specifically, we identified sidekick-1-important for synaptic connections during development-as a critical PARP-1 target gene involved in cocaine's behavioral effects as well as in its ability to induce dendritic spines on NAc neurons. These findings establish the involvement of PARP-1 and PARylation in the long-term actions of cocaine. c57bl/6 mice were given IP injections of chronic cocaine 20mg/kg once per day for 7 days and sacrificed 30 minutes after the final dose of cocaine. Control animals were given saline for 7 days and sacrificed 30 minutes after the final dose of saline. Nucleus accumbens (NAc) tissue was collected and then PARP-1 ChIP-seq was performed. Three sequencing replicates were performed on each group.
2014-02-20 | E-GEOD-55136 | biostudies-arrayexpress
Project description:Despite addiction being one of the most prevalent and debilitating disorders worldwide, effective treatments are lacking. Repeated cocaine exposure induces maladaptive transcriptional regulation within the brainâ??s reward circuitry, such as the nucleus accumbens (NAc), and epigenetic mechanisms, such as histone acetylation or methylation on Lys (K) residues, have been linked to these lasting actions of cocaine. However, in contrast to K methylation, the functional role of histone Arg (R) methylation remains unexplored in addiction models and poorly understood in brain in general. Here we show that protein-R-methyltransferase-6 (PRMT6) and its associated histone mark, asymmetric dimethylation of R2 on histone H3 (H3R2me2a), are decreased in the NAc of mice and rats after repeated cocaine exposure, as well as in the NAc of cocaine-addicted humans. PRMT6 downregulation occurs selectively in NAc medium spiny neurons expressing dopamine D2 receptors (D2-MSNs) and serves to protect against cocaine-induced addictive-like behavioral abnormalities. Using ChIP-seq, we demonstrate that reduced H3R2me2a binding at gene targets in NAc after repeated cocaine is strongly correlated with increased binding of H3K4me3, and identify Src kinase signaling inhibitor 1 (Srcin1 or p140Cap) as a key gene for these chromatin modifications. Cocaine induction of Srcin1 in NAc, which is associated with reduced Src signaling, decreases cocaine reward, the motivation to self administer cocaine, and cocaine-induced changes in NAc MSN dendritic spines. These results suggest that this suppression of Src signaling in NAc D2-MSNs, via PRMT6 and H3R2me2a downregulation, functions as a homeostatic brake to restrain cocaine action, and provide novel candidates for the development of new treatments for cocaine addiction. H3R2me2A ChIP-seq of mouse. Cocaine vs Saline, 3 biological replicates.
2016-08-08 | E-GEOD-85310 | biostudies-arrayexpress
Project description:Many of the long-term effects of cocaine on the brain's reward circuitry have been shown to be mediated by alterations in gene expression. Several chromatin modifications, including histone acetylation and methylation, have been implicated in this regulation, but the effect of other histone modifications remains poorly understood. Poly(ADP-ribose) polymerase-1 (PARP-1), a ubiquitous and abundant nuclear protein, catalyzes the synthesis of a negatively charged polymer called poly(ADP-ribose) or PAR on histones and other substrate proteins and forms transcriptional regulatory complexes with several other chromatin proteins. Here, we identify an essential role for PARP-1 in cocaine-induced molecular, neural, and behavioral plasticity. Repeated cocaine administration, including self-administration, increased global levels of PARP-1 and its mark PAR in mouse nucleus accumbens (NAc), a key brain reward region. Using PARP-1 inhibitors and viral-mediated gene transfer, we established that PARP-1induction in NAc mediates enhanced behavioral responses to cocaine, including increased self-administration of the drug. Using chromatin immunoprecipitation sequencing, we demonstrated a global, genome-wide enrichment of PARP-1 in NAc of cocaine-exposed mice and identified several PARP-1 target genes that could contribute to the lasting effects of cocaine. Specifically, we identified sidekick-1-important for synaptic connections during development-as a critical PARP-1 target gene involved in cocaine's behavioral effects as well as in its ability to induce dendritic spines on NAc neurons. These findings establish the involvement of PARP-1 and PARylation in the long-term actions of cocaine.
2014-02-20 | GSE55136 | GEO
Project description:Here we show that Tet1 is down-regulated in mouse nucleus accumbens (NAc), a key brain reward structure, by repeated cocaine administration which enhances behavioral responses to cocaine. Through genome-wide 5hmC profiling, we identified 5hmC changes selectively clustered in both enhancer and coding regions of genes with several annotated neural functions. By coupling with mRNA sequencing, we found cocaine-induced alterations in 5hmC correlate positively with alternative splicing. We also demonstrated that 5hmC alteration at certain genes lasts up to a month after cocaine exposure. RNA Nac samples were collected at various time points after 7 daily cocaoine ip administration for 5hmC and transcriptome analysis
2015-02-23 | E-GEOD-63748 | biostudies-arrayexpress
Project description:Here we show that Tet1 is down-regulated in mouse nucleus accumbens (NAc), a key brain reward structure, by repeated cocaine administration which enhances behavioral responses to cocaine. Through genome-wide 5hmC profiling, we identified 5hmC changes selectively clustered in both enhancer and coding regions of genes with several annotated neural functions. By coupling with mRNA sequencing, we found cocaine-induced alterations in 5hmC correlate positively with alternative splicing. We also demonstrated that 5hmC alteration at certain genes lasts up to a month after cocaine exposure. DNA Nac samples were collected at various time points after 7 daily cocaoine ip administration for 5hmC and transcriptome analysis
2015-02-23 | E-GEOD-63747 | biostudies-arrayexpress
Project description:Long-lasting changes in neuronal gene expression in brain reward regions, including the nucleus accumbens (NAc), contribute to the persistent functional changes in the addicted brain. Our group and others have demonstrated that altered expression or activity of several candidate transcription factors in NAc regulates drug responses. In a recent study from our group (Feng et al., 2014), involving large-scale genome-wide datasets, E2F3 was predicted as a prominent upstream regulator of cocaine-induced changes in gene expression and alternative splicing. Here, we show that E2F3a, but not E2F3b, expression in NAc regulates cocaine-induced locomotor and reward behavior. Furthermore, we demonstrate that E2F3a overexpression recapitulates a considerable portion of genome-wide transcriptional profiles and alternative splicing induced by cocaine administration. We further validate functional binding of E2F3a at several target genes following cocaine exposure. These novel findings support a crucial role for E2F3a in the regulation of cocaine-elicited behavioral states and molecular mechanisms.
2017-08-23 | GSE85936 | GEO
Project description:Despite addiction being one of the most prevalent and debilitating disorders worldwide, effective treatments are lacking. Repeated cocaine exposure induces maladaptive transcriptional regulation within the brain’s reward circuitry, such as the nucleus accumbens (NAc), and epigenetic mechanisms, such as histone acetylation or methylation on Lys (K) residues, have been linked to these lasting actions of cocaine. However, in contrast to K methylation, the functional role of histone Arg (R) methylation remains unexplored in addiction models and poorly understood in brain in general. Here we show that protein-R-methyltransferase-6 (PRMT6) and its associated histone mark, asymmetric dimethylation of R2 on histone H3 (H3R2me2a), are decreased in the NAc of mice and rats after repeated cocaine exposure, as well as in the NAc of cocaine-addicted humans. PRMT6 downregulation occurs selectively in NAc medium spiny neurons expressing dopamine D2 receptors (D2-MSNs) and serves to protect against cocaine-induced addictive-like behavioral abnormalities. Using ChIP-seq, we demonstrate that reduced H3R2me2a binding at gene targets in NAc after repeated cocaine is strongly correlated with increased binding of H3K4me3, and identify Src kinase signaling inhibitor 1 (Srcin1 or p140Cap) as a key gene for these chromatin modifications. Cocaine induction of Srcin1 in NAc, which is associated with reduced Src signaling, decreases cocaine reward, the motivation to self administer cocaine, and cocaine-induced changes in NAc MSN dendritic spines. These results suggest that this suppression of Src signaling in NAc D2-MSNs, via PRMT6 and H3R2me2a downregulation, functions as a homeostatic brake to restrain cocaine action, and provide novel candidates for the development of new treatments for cocaine addiction.
2016-08-08 | GSE85310 | GEO
Project description:ATP-dependent chromatin remodeling proteins are being implicated increasingly in the regulation of complex behaviors, including models of several psychiatric disorders. Here, we demonstrate that Baz1b, an accessory subunit of the ISWI family of chromatin remodeling complexes, is upregulated in the nucleus accumbens (NAc), a key brain reward region, in both chronic cocaine-treated mice and mice that are resilient to chronic social defeat stress. In contrast, no regulation is seen in mice that are susceptible to this chronic stress. Viral-mediated overexpression of Baz1b, along with its associated subunit Smarca5, in mouse NAc is sufficient to potentiate both rewarding responses to cocaine, including cocaine self-administration, and resilience to chronic social defeat stress. However, despite these similar, proreward behavioral effects, genome-wide mapping of BAZ1B in NAc revealed mostly distinct subsets of genes regulated by these chromatin remodeling proteins after chronic exposure to either cocaine or social stress. Together, these findings suggest important roles for BAZ1B and its associated chromatin remodeling complexes in NAc in the regulation of reward behaviors to distinct emotional stimuli and highlight the stimulus-specific nature of the actions of these regulatory proteins. BAZ1B (WSTF) ChIP-seq of mouse. Cocaine vs Saline, 3 biological replicates. In social defeat model: Normal control vs Susceptible vs Resilient, 3 biological replicates.
2016-07-30 | E-GEOD-85005 | biostudies-arrayexpress