Role of Tet1 and 5-hydroxymethylcytosine in cocaine action (5hmC-Seq and ChIP-Seq)
Ontology highlight
ABSTRACT: 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
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
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.
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.
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.
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.
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:Here, we explore the function of a drug-associated repressive transcription factor (TF), ZFP189, whose expression in the nucleus accumbens (NAc) facilitates cocaine-induced molecular and behavioral adaptations. To uncover the molecular action of ZFP189, we created synthetic ZFP189 TFs of distinct transcriptional function, including ZFP189VPR, which activates the expression of target genes and exerts opposite transcriptional control to the endogenously repressive ZFP189. By virally delivering synthetic ZFP189 TFs to the NAc of mice, we discover that the molecular control exerted by synthetic or endogenous ZFP189 solely alters behavioral response to cocaine but not morphine or palatable food. Transcriptional adaptation occurred in response to cocaine, but not morphine. We demonstrate that NAc ZFP189 function drives the cocaine self-administration behaviors, whereas NAc ZFP189VPR impedes this worsening of cocaine taking behaviors. Collectively, this research illuminates the mechanisms through which a drug-associated TF specifically coordinates the brain adaptations necessary for the increasing of cocaine self-administration behaviors.
Project description:ATRX is a member of the SWI2/SNF2 family of chromatin remodeling proteins and primarily functions at heterochromatic loci via its recognition of M-bM-^@M-^XrepressiveM-bM-^@M-^Y histone modifications (e.g., H3K9me3). Despite significant roles for ATRX during normal neural development, as well as its relationship to human disease, ATRX function in the central nervous system is not well understood. Here, we describe ATRXM-bM-^@M-^Ys ability to recognize an activity-dependent combinatorial histone modification, H3K9me3S10ph, in post-mitotic neurons. In neurons, this M-bM-^@M-^\methyl/phosM-bM-^@M-^] switch occurs exclusively following periods of stimulation and is highly enriched at heterochromatic repeats associated with centromeres. Using a multifaceted approach, we reveal that H3K9me3S10ph bound Atrx represses non-coding transcription of centromeric minor satellite sequences during instances of heightened activity. Our results indicate an essential interaction between ATRX and a previously uncharacterized histone modification in the central nervous system and suggest a potential role for abnormal repetitive element transcription in pathological states manifested by ATRX dysfunction. For Atrx ChIP-seq, IPs were performed on three control vs. three KCl stimulated (all representing biological, and not technical replicates) primary cultured mouse cortical neurons at DIV 8. All samples were normalized to background input levels. For H3K9me3S10phos ChIP-seq, biological singlecates (control vs. forskolin) were analyzed against respective inputs.
Project description:Substance use disorder (SUD) is a chronic neuropsychiatric condition characterized by long-lasting alterations in the neural circuitry regulating reward and motivation. Substantial work has focused on characterizing the molecular substrates which underlie these persistent changes in neural function and behavior; however, this work has overwhelmingly focused on male subjects, despite mounting clinical and preclinical evidence that females demonstrate dissimilar progression to SUD and responsivity to drugs of abuse, such as cocaine. Here, we show that sex is a critical biological variable that defines drug-induced plasticity in the NAc. Using quantitative mass spectrometry, we assessed the protein expression patterns altered by cocaine self-administration and demonstrate unique molecular profiles between males and females. We show that 1. Cocaine self-administration induces non-overlapping protein expression patterns in males and females and 2. Cocaine specifically acts on baseline sexual dimorphisms to exert these effects. Critically, we find that cocaine administration blunts not only basal sex-differences in the accumbens proteome, but also the pre-existing sex differences in behavior for natural rewards. Together, these data suggest that chronic cocaine is capable of rewriting baseline proteomic function to maintain cocaine-specific behaviors.
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.