ABSTRACT: Reward-related memory is an important factor in cocaine seeking. One necessary signaling mechanism for long-term memory formation is the activation of poly(ADP-ribose) polymerase-1 (PARP-1), via poly(ADP-ribosyl)ation. We demonstrate herein that auto-poly(ADP-ribosyl)ation of activated PARP-1 was significantly pronounced during retrieval of cocaine-associated contextual memory, in the central amygdala (CeA) of rats expressing cocaine-conditioned place preference (CPP). Intra-CeA pharmacological and shRNA depletion of PARP-1 activity during cocaine-associated memory retrieval abolished CPP. In contrast, PARP-1 inhibition after memory retrieval did not affect CPP reconsolidation process and subsequent retrievals. Chromatin Immuoprecipitation (ChIP) sequencing revealed that PARP-1 binding in the CeA is highly enriched in genes involved in neuronal signaling. We identified amongst PARP targets in CeA a single gene, yet uncharacterized and encoding a putative transposase inhibitor, at which PARP-1 enrichment dramatically increases during cocaine-associated memory retrieval and positively correlates with CPP. Our findings have important implications for understanding drug-related behaviors, and suggest possible future therapeutic targets for drug abuse.
Project description:Reward-related memory is an important factor in cocaine seeking. One necessary signaling mechanism for long-term memory formation is the activation of poly(ADP-ribose) polymerase-1 (PARP-1), via poly(ADP-ribosyl)ation. We demonstrate herein that auto-poly(ADP-ribosyl)ation of activated PARP-1 was significantly pronounced during retrieval of cocaine-associated contextual memory, in the central amygdala (CeA) of rats expressing cocaine-conditioned place preference (CPP). Intra-CeA pharmacological and shRNA depletion of PARP-1 activity during cocaine-associated memory retrieval abolished CPP. In contrast, PARP-1 inhibition after memory retrieval did not affect CPP reconsolidation process and subsequent retrievals. Chromatin Immuoprecipitation (ChIP) sequencing revealed that PARP-1 binding in the CeA is highly enriched in genes involved in neuronal signaling. We identified amongst PARP targets in CeA a single gene, yet uncharacterized and encoding a putative transposase inhibitor, at which PARP-1 enrichment dramatically increases during cocaine-associated memory retrieval and positively correlates with CPP. Our findings have important implications for understanding drug-related behaviors, and suggest possible future therapeutic targets for drug abuse. 4 samples, each is pooled central amygdalae tissues collected from 2 rats. Rats were trained for cocaine-conditioned place-preference (CPP), tissues were harvested immediately following cocaine-CPP retrieval. Three groups of rats were used: high cocaine CPP, low cocaine CPP and control saline only trained rats.
Project description:Drosophila Insulator proteins mediate long-range chromosomal interactions. ChIP-seq revealed that binding of insulator proteins to some specific DNA sites was regulated by poly(ADP-ribosyl)ation in S2 cells. Three insulator sites regulated by poly(ADP-ribosyl)ation were used as baits to map their distant interacting sites using 4C assay in control S2 cells. Mapping the chromosomal interactions of three specific insulator binding sites with 4C assay in control S2 cells.
Project description:Drosophila Insulator proteins mediate long-range chromosomal interactions. ChIP-seq revealed that binding of insulator proteins to some specific DNA sites was regulated by poly(ADP-ribosyl)ation in S2 cells. Three insulator sites regulated by poly(ADP-ribosyl)ation were used as baits to map their distant interacting sites using 4C assay in control S2 cells.
Project description:Genome-wide gene expression analysis of the effects of PARP inhibitor (3AB) and, separately, a parg1 knockout, on early microbe-associate molecular pattern (MAMP)-induced gene expression in the plant basal defense response. Arabidopsis thaliana wild-type (Col-0), 3AB-treated and parg1-2 T-DNA knockout plants responding to the MAMP elicitors flg22 or elf18 were studied. The mutant and PARP inhibitors analyzed in this study are further described in Adams-Phillips, L.,C., Briggs, A.,G., Bent, A., F. 2010. Disruption of poly(ADP-ribosyl)ation mechanisms alters responses of Arabidopsis to biotic stress. Planty Physiol. 152(1):267-80 DOI: 10.1104/pp.109.148049.
Project description:Post-translational modifications, such as poly(ADP-ribosyl)ation (PARylation), regulate chromatin-modifying enzymes, ultimately affecting gene expression. This study explores the role of poly(ADP-ribose) polymerase (PARP) on global gene expression in a lymphoblastoid B cell line. We found that inhibition of PARP catalytic activity with olaparib resulted in global gene deregulation, affecting approximately 11% of genes expressed. Gene ontology analysis revealed that PARP could exert these effects through transcription factors and chromatin-remodeling enzymes, including the Polycomb Repressive Complex 2 (PRC2) member EZH2. EZH2 mediates the trimethylation of histone H3 at lysine 27 (H3K27me3), a modification associated with chromatin compaction and gene silencing. Both pharmacological inhibition of PARP and knockdown of PARP1 induced the expression of EZH2 that resulted in increased global H3K27me3. Chromatin immunoprecipitation confirmed that PARP1 inhibition led to H3K27me3 deposition at EZH2-target genes, which resulted in gene silencing. Moreover, increased EZH2 expression is attributed to occupancy loss of the transcription repressor E2F4 at the EZH2 promoter following PARP inhibition. Together, these data show that PARP plays an important role in global gene regulation and identifies for the first time a direct role of PARP1 in regulating the expression and function of EZH2.
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:Substance use disorder emerges in a small proportion of drug users and has the characteristics of a chronic relapsing pathology. The objective of our study was to demonstrate and characterize the variability in the expression of the reinforcing effects of cocaine in the conditioned place preference (CPP) paradigm. An unbiased cocaine-CPP paradigm in Sprague-Dawley rats with an extinction period of 12 days and reinstatement was conducted. We developed a statistical model to distinguish rats that express or do not express cocaine-induced place preference. Two groups of rats were identified: rats that did express reinforcing effects (CPP expression (CPPE), score > 102 s) and rats that did not (no CPP expression (nCPPE), score between −85 and 59 s). These two groups did not show significant differences in a battery of behavioral tests. To identify differentially expressed genes in the CPPE and nCPPE groups, we performed a whole-transcriptome RNA-sequencing analysis in the nucleus accumbens (Nac) 24 h after the CPP test. Four immediate early genes (Fos, Egr2, Nr4a1 and Zbtb37) were differentially expressed in the Nac of CPPE rats after CPP memory retrieval. Variability in cocaine-induced place preference persisted in the CPPE and nCPPE groups after the extinction and reinstatement phases. Transcriptomic differences observed after reinstatement were distinct from those observed immediately after CPP memory retrieval. These new findings provide insights into the identification of mechanisms underlying interindividual variability in the response to cocaine's reinforcing effects.
Project description:Substance use disorder emerges in a small proportion of drug users and has the characteristics of a chronic relapsing pathology. The objective of our study was to demonstrate and characterize the variability in the expression of the reinforcing effects of cocaine in the conditioned place preference (CPP) paradigm. An unbiased cocaine-CPP paradigm in Sprague-Dawley rats with an extinction period of 12 days and reinstatement was conducted. We developed a statistical model to distinguish rats that express or do not express cocaine-induced place preference. Two groups of rats were identified: rats that did express reinforcing effects (CPP expression (CPPE), score > 102 s) and rats that did not (no CPP expression (nCPPE), score between −85 and 59 s). These two groups did not show significant differences in a battery of behavioral tests. To identify differentially expressed genes in the CPPE and nCPPE groups, we performed a whole-transcriptome RNA-sequencing analysis in the nucleus accumbens (Nac) 24 h after the CPP test. Four immediate early genes (Fos, Egr2, Nr4a1 and Zbtb37) were differentially expressed in the Nac of CPPE rats after CPP memory retrieval. Variability in cocaine-induced place preference persisted in the CPPE and nCPPE groups after the extinction and reinstatement phases. Transcriptomic differences observed after reinstatement were distinct from those observed immediately after CPP memory retrieval. These new findings provide insights into the identification of mechanisms underlying interindividual variability in the response to cocaine's reinforcing effects.
Project description:Reduced p62 levels are associated with the induction of the cancer-associated fibroblast (CAF) phenotype, which promotes tumorigenesis in vitro and in vivo through inflammation and metabolic reprogramming. However, how p62 is downregulated in the stroma fibroblasts by tumor cells to drive CAF activation is an unresolved central issue in the field. Here we show that tumor-secreted lactate downregulate p62 transcriptionally through a mechanism involving reduction of the NAD+/NADH ratio, which impaired poly(ADP-Ribose)-polymerase 1 (PARP1) activity. PARP1 inhibition blocked the poly(ADP-ribosyl)ation of the AP1 transcription factors, c-FOS and c-JUN, which is an obligate step for p62 downregulation. Importantly, restoring p62 levels in CAFs by NAD+ rendered CAFs less active. PARP inhibitors, such as Olaparib, mimicked lactate in the reduction of stromal p62 levels, as well as the subsequent stromal activation both in vitro and in vivo, which suggests that therapies utilizing Olaparib would benefit from strategies aimed at inhibiting CAF activity.