1 775 156 CELL TYPE-SPECIFIC WHOLE-GENOME LANDSCAPE OF DELTAFOSB BINDING IN THE NUCLEUS ACCUMBENS AFTER CHRONIC COCAINE EXPOSURE. BACKGROUND: THE ABILITY OF NEURONS TO RESPOND TO EXTERNAL STIMULI INVOLVES ADAPTATIONS OF GENE EXPRESSION. INDUCTION OF THE TRANSCRIPTION FACTOR DELTAFOSB IN THE NUCLEUS ACCUMBENS, A KEY BRAIN REWARD REGION, IS IMPORTANT FOR THE DEVELOPMENT OF DRUG ADDICTION. HOWEVER, A COMPREHENSIVE MAP OF DELTAFOSB'S GENE TARGETS HAS NOT YET BEEN GENERATED. METHODS: WE USED CUT&RUN (CLEAVAGE UNDER TARGETS AND RELEASE USING NUCLEASE) TO MAP THE GENOME-WIDE CHANGES IN DELTAFOSB BINDING IN THE 2 MAIN TYPES OF NUCLEUS ACCUMBENS NEURONS-D1 OR D2 MEDIUM SPINY NEURONS-AFTER CHRONIC COCAINE EXPOSURE. TO ANNOTATE GENOMIC REGIONS OF DELTAFOSB BINDING SITES, WE ALSO EXAMINED THE DISTRIBUTIONS OF SEVERAL HISTONE MODIFICATIONS. RESULTING DATASETS WERE LEVERAGED FOR MULTIPLE BIOINFORMATIC ANALYSES. RESULTS: THE MAJORITY OF DELTAFOSB PEAKS OCCUR OUTSIDE PROMOTER REGIONS, INCLUDING INTERGENIC REGIONS, AND ARE SURROUNDED BY EPIGENETIC MARKS INDICATIVE OF ACTIVE ENHANCERS. BRG1, THE CORE SUBUNIT OF THE SWI/SNF CHROMATIN REMODELING COMPLEX, OVERLAPS WITH DELTAFOSB PEAKS, A FINDING CONSISTENT WITH EARLIER STUDIES OF DELTAFOSB'S INTERACTING PROTEINS. CHRONIC COCAINE USE INDUCES BROAD CHANGES IN DELTAFOSB BINDING IN BOTH D1 AND D2 NUCLEUS ACCUMBENS MEDIUM SPINY NEURONS OF MALE AND FEMALE MICE. IN ADDITION, IN SILICO ANALYSES PREDICT THAT DELTAFOSB COOPERATIVELY REGULATES GENE EXPRESSION WITH HOMEOBOX AND T-BOX TRANSCRIPTION FACTORS. CONCLUSIONS: THESE NOVEL FINDINGS UNCOVER KEY ELEMENTS OF DELTAFOSB'S MOLECULAR MECHANISMS IN TRANSCRIPTIONAL REGULATION AT BASELINE AND IN RESPONSE TO CHRONIC COCAINE EXPOSURE. FURTHER CHARACTERIZATION OF DELTAFOSB'S COLLABORATIVE TRANSCRIPTIONAL AND CHROMATIN PARTNERS SPECIFICALLY IN D1 AND D2 MEDIUM SPINY NEURONS WILL REVEAL A BROADER PICTURE OF THE FUNCTION OF DELTAFOSB AND THE MOLECULAR BASIS OF DRUG ADDICTION. 2023 2 2366 28 EPIGENETIC REGULATION OF STEROIDOGENIC ENZYMES EXPRESSED IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM HEALTHY INDIVIDUALS AND FROM PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA. SEX HORMONE SYNTHESIS OCCURS IN VARIOUS ORGANS AND TISSUES BESIDES THE GONADS, SUCH AS ADRENAL GLANDS, BRAIN, INTESTINES, SKIN, FAT, BONE, AND CELLS OF THE IMMUNE SYSTEM. REGARDING THE LATTER, IT IS STILL NOT CLEAR WHICH PATHWAYS ARE ACTIVE, AND IF THEY ARE MODIFIED IN CASE OF ILLNESS OF THE IMMUNE SYSTEM. OUR GOAL IN THIS STUDY WAS TO DETERMINE MRNA EXPRESSION OF DIFFERENT STEROIDOGENIC ENZYMES IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM HEALTHY INDIVIDUALS OF BOTH SEXES AND OF DIFFERENT AGES, AND THEN TO COMPARE THEIR EXPRESSION BETWEEN HEALTHY INDIVIDUALS AND PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). FURTHERMORE, TO ELUCIDATE POSSIBLE MECHANISMS THAT REGULATE ENZYME EXPRESSION, WE ANALYZED EPIGENETIC EVENTS LIKE PROMOTER METHYLATION. WE DETERMINED THAT NORMAL CELLS OF THE IMMUNE SYSTEM, REGARDLESS OF SEX AND AGE, EXPRESSED P450 SIDE CHAIN CLEAVAGE (P450SCC), CYTOCHROME P450 17ALPHA-HYDROXYLASE/C17,20-LYASE (P45017ALPHA), 3BETA-HYDROXYSTEROID DEHYDROGENASE/DELTA5-DELTA4-ISOMERASE (3BETA-HSD), STEROID 5 ALPHA REDUCTASE (5ALPHA-R) TYPES 1, 2 AND 3, 3ALPHA-HYDROXYSTEROID DEHYDROGENASE (3ALPHA-HSD) TYPE 3, AND 17BETA-HYDROXYSTEROID DEHYDROGENASE (17BETA-HSD) TYPES 1, 3 AND 5. WE ALSO ESTABLISHED THAT 5ALPHA-R 1, 5ALPHA-R 3, 3ALPHA-HSD 3, 17BETA-HSD 1 AND 17BETA-HSD 5 EXPRESSION WAS ALTERED IN CLL PATIENTS, AND THAT PROMOTER REGIONS OF 5ALPHA-R 1, 17BETA-HSD 1 AND 17BETA-HSD 5 WERE DIFERENTIALLY METHYLATED. THESE RESULTS SUGGEST THAT STEROIDOGENIC PATHWAYS MAY BE AFFECTED IN CLL CELLS, AND THIS COULD BE RELATED TO DISEASE PATHOGENESIS. 2020 3 5823 33 STRESS INCREASES DNA METHYLATION OF THE NEURONAL PAS DOMAIN 4 (NPAS4) GENE. NEURONAL PER ARNT SIM DOMAIN 4 (NPAS4), A BRAIN-SPECIFIC HELIX-LOOP-HELIX TRANSCRIPTION FACTOR, WAS RECENTLY SHOWN TO REGULATE THE DEVELOPMENT OF GABAERGIC INHIBITORY NEURONS. NPAS4 MRNA EXPRESSION LEVELS WERE DECREASED IN THE HIPPOCAMPUS OF MICE EXPOSED TO STRESS, WHICH WAS ACCOMPANIED BY BRAIN DYSFUNCTION. WE HAVE SUGGESTED THAT TRANSIENT STRESS REDUCED NPAS4 TRANSCRIPTION THROUGH THE GLUCOCORTICOID RECEPTOR. IN THE PRESENT REPORT, WE INVESTIGATED THE POTENTIAL CONTRIBUTION OF EPIGENETIC MODIFICATIONS INDUCED BY STRESS ON NPAS4 GENE EXPRESSION. THE NPAS4 PROMOTER REGION CONTAINS TWO CPG ISLANDS; IN THE HIPPOCAMPUS, CHRONIC RESTRAINT STRESS INCREASES THE DNA METHYLATION LEVELS OF BOTH OF THESE CPG ISLANDS. IN THE NEURO2A CELL LINE, TREATMENT WITH A DNA METHYLTRANSFERASE INHIBITOR, 5-AZA-2'-DEOXYCYTIDINE, INCREASED NPAS4 MRNA LEVELS AND MARKEDLY REDUCED THE DNA METHYLATION LEVELS OF CPG ISLAND 2 IN THE NPAS4 PROMOTER. THE DNA METHYLATION SITES IN CPG ISLAND 2 OVERLAP WITH TWO CYCLIC ADENOSINE MONOPHOSPHATE RESPONSE ELEMENT (CRE) SEQUENCES. MUTATION OF THESE CRE SEQUENCES REDUCED NPAS4 PROMOTER ACTIVITY. THESE RESULTS SUGGEST THAT TRANSCRIPTION OF THE NPAS4 GENE IS DOWNREGULATED BY STRESS THROUGH DNA METHYLATION OF ITS PROMOTER. 2015 4 2326 32 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 5 2300 34 EPIGENETIC REGULATION OF BDNF EXPRESSION IN THE PRIMARY SENSORY NEURONS AFTER PERIPHERAL NERVE INJURY: IMPLICATIONS IN THE DEVELOPMENT OF NEUROPATHIC PAIN. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS KNOWN TO BE UP-REGULATED IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, AND TO CONTRIBUTE TO NEUROPATHIC PAIN. HERE, WE FOUND THAT THERMAL HYPERALGESIA AND MECHANICAL ALLODYNIA AT DAY 7 POST-INJURY WERE INHIBITED ONLY WHEN ANTI-BDNF ANTIBODY WAS INTRATHECALLY ADMINISTRATED AT DAY 2 POST-INJURY. CONSISTENT WITH BEHAVIORAL RESULTS, WESTERN BLOT ANALYSIS SHOWED THAT THE EXPRESSION LEVELS OF BDNF PROTEIN IN THE SPINAL DORSAL HORN WERE MARKEDLY INDUCED DURING EARLY STAGE POST-INJURY. MOREOVER, THE MAXIMAL INCREASE IN BDNF MRNA EXPRESSION IN THE DRG WAS OBSERVED AT DAY 1 POST-INJURY, AND SIGNIFICANTLY ELEVATED LEVELS WERE SUSTAINED FOR AT LEAST 14 DAYS. FOUR OF FIVE BDNF MRNA TRANSCRIPTS WERE UP-REGULATED AFTER NERVE INJURY, AND THE MOST INDUCIBLE TRANSCRIPT WAS EXON I. USING A CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, WE FOUND THAT NERVE INJURY PROMOTES HISTONE H3 AND H4 ACETYLATION, TRANSCRIPTIONALLY ACTIVE MODIFICATIONS, AT BDNF PROMOTER I AT DAY 1 POST-INJURY, AND THE LEVELS OF HISTONE ACETYLATION REMAIN ELEVATED FOR AT LEAST 7 DAYS. TAKEN TOGETHER, OUR FINDINGS SUGGEST THAT AN INITIAL INCREASE IN BDNF EXON I EXPRESSION CONTROLLED BY EPIGENETIC MECHANISMS MIGHT HAVE A CRUCIAL ROLE IN THE DEVELOPMENT OF NEUROPATHIC PAIN. 2013 6 1620 37 DNA METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL SILENCING IN MALIGNANT GLIOMA: A COMBINED WHOLE-GENOME MICROARRAY AND PROMOTER ARRAY ANALYSIS. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS A COMMON FEATURE IN HUMAN CANCER. PROMOTER HYPERMETHYLATION AND HISTONE DEACETYLATION ARE REVERSIBLE EPIGENETIC MECHANISMS ASSOCIATED WITH TRANSCRIPTIONAL REGULATION. DNA METHYLTRANSFERASES (DNMT1 AND DNMT3B) REGULATE AND MAINTAIN PROMOTER METHYLATION AND ARE OVEREXPRESSED IN HUMAN CANCER. WE PERFORMED WHOLE-GENOME MICROARRAY ANALYSIS TO IDENTIFY GENES WITH ALTERED EXPRESSION AFTER RNAI-INDUCED SUPPRESSION OF DNMT IN A GLIOBLASTOMA MULTIFORME (GBM) CELL LINE. WE THEN IDENTIFIED GENES WITH BOTH DECREASED EXPRESSION AND EVIDENCE OF PROMOTER CPG ISLAND HYPERMETHYLATION IN GBM TISSUE SAMPLES USING A COMBINED WHOLE-GENOME MICROARRAY TRANSCRIPTOME ANALYSIS IN CONJUNCTION WITH A PROMOTER ARRAY ANALYSIS AFTER DNA IMMUNOPRECIPITATION WITH ANTI-5-METHYLCYTIDINE. DNMT1 AND 3B KNOCKDOWN RESULTED IN THE RESTORED EXPRESSION OF 308 GENES THAT ALSO CONTAINED PROMOTER REGION HYPERMETHYLATION. OF THESE, 43 WERE ALSO FOUND TO BE DOWNREGULATED IN GBM TISSUE SAMPLES. THREE DOWNREGULATED GENES WITH HYPERMETHYLATED PROMOTERS AND RESTORED EXPRESSION IN RESPONSE TO ACUTE DNMT SUPPRESSION WERE ASSAYED FOR METHYLATION CHANGES USING BISULFITE SEQUENCE ANALYSIS OF THE PROMOTER REGION AFTER CHRONIC DNMT SUPPRESSION. RESTORATION OF GENE EXPRESSION WAS NOT ASSOCIATED WITH CHANGES IN PROMOTER REGION METHYLATION, BUT RATHER WITH CHANGES IN HISTONE METHYLATION AND CHROMATIN CONFORMATION. TWO OF THE IDENTIFIED GENES EXHIBITED GROWTH SUPPRESSIVE ACTIVITY IN IN VITRO ASSAYS. COMBINING TARGETED GENETIC MANIPULATIONS WITH COMPREHENSIVE GENOMIC AND EXPRESSION ANALYSES PROVIDES A POTENTIALLY POWERFUL NEW APPROACH FOR IDENTIFYING EPIGENETICALLY REGULATED GENES IN GBM. 2009 7 1831 34 EFFECTS OF MATERNAL SEPARATION AND ANTIDEPRESSANT DRUG ON EPIGENETIC REGULATION OF THE BRAIN-DERIVED NEUROTROPHIC FACTOR EXON I PROMOTER IN THE ADULT RAT HIPPOCAMPUS. AIM: EARLY LIFE STRESS CAN INDUCE EPIGENETIC CHANGES THROUGH GENETIC AND ENVIRONMENTAL INTERACTIONS AND IS A RISK FACTOR FOR DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN IMPLICATED IN THE PATHOPHYSIOLOGY OF DEPRESSION AND ANTIDEPRESSANT DRUG ACTION. WE INVESTIGATED EPIGENETIC CHANGES AT THE BDNF EXON I PROMOTER IN THE HIPPOCAMPUS OF ADULT RATS SUBJECTED TO MATERNAL SEPARATION (MS) DURING EARLY LIFE AND TREATED WITH AN ANTIDEPRESSANT DRUG AS ADULTS. METHODS: RAT PUPS WERE SUBJECTED TO MS FROM POSTNATAL DAY 1 TO 21 AND RECEIVED CHRONIC ESCITALOPRAM (ESC) AS ADULTS. WE ASSESSED THE EFFECTS OF MS AND ESC ON BDNF EXON I AND DNA METHYLTRANSFERASES (DNMT) MRNA LEVELS (QUANTITATIVE REVERSE-TRANSCRIPTION POLYMERASE CHAIN REACTION), ACETYLATED HISTONE H3, AND MECP2 BINDING TO THE BDNF PROMOTER I (CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY REAL-TIME POLYMERASE CHAIN REACTION), AND BDNF PROTEIN LEVELS (ENZYME-LINKED IMMUNOSORBENT ASSAY). RESULTS: THE LEVELS OF BDNF PROTEIN, EXON I MRNA, HISTONE H3 ACETYLATION, AND DNMT1 AND DNMT3A MRNA WERE ALTERED IN THE MS GROUP COMPARED WITH THE CONTROL GROUP. SIGNIFICANT DECREASES WERE OBSERVED IN THE BDNF PROTEIN, EXON I MRNA, AND HISTONE H3 ACETYLATION LEVELS AND THERE WERE SIGNIFICANT INCREASES IN DNMT1 AND DNMT3A MRNA LEVELS. THE COMPARISON BETWEEN THE MS + ESC AND MS GROUPS REVEALED SIGNIFICANT INCREASES IN BDNF PROTEIN, EXON I MRNA, AND HISTONE H3 ACETYLATION LEVELS AND SIGNIFICANT DECREASES IN MECP2 AND DNMT1 AND DNMT3A MRNA LEVELS. CONCLUSION: THESE FINDINGS INDICATE THAT MS INDUCED EPIGENETIC CHANGES AT THE BDNF EXON I PROMOTER AND THESE CHANGES WERE PREVENTED BY ANTIDEPRESSANT DRUG TREATMENT DURING ADULTHOOD. 2018 8 6069 32 THE DIOXIN RECEPTOR IS SILENCED BY PROMOTER HYPERMETHYLATION IN HUMAN ACUTE LYMPHOBLASTIC LEUKEMIA THROUGH INHIBITION OF SP1 BINDING. THE TRANSCRIPTION FACTOR ARYL HYDROCARBON RECEPTOR (AHR) HAS RELEVANT FUNCTIONS IN CELL PROLIFERATION. INTERESTINGLY, THE AHR CAN EITHER PROMOTE OR INHIBIT PROLIFERATION DEPENDING ON THE CELL PHENOTYPE. ALTHOUGH RECENT DATA REVEAL POTENTIAL PATHWAYS FOR AHR SIGNALING IN CELL PROLIFERATION, THE MECHANISMS THAT REGULATE ITS ACTIVITY IN TUMOR CELLS REMAIN UNKNOWN. HERE, WE HAVE ANALYZED PROMOTER HYPERMETHYLATION AS A POTENTIAL MECHANISM CONTROLLING AHR EXPRESSION IN HUMAN TUMOR CELLS. AHR PROMOTER CPG METHYLATION WAS SPORADIC IN A PANEL OF 19 TUMOR CELL LINES EXCEPT FOR THE CHRONIC MYELOID LEUKEMIA (CML) K562 AND THE ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) REH. WHEN COMPARED WITH NORMAL LYMPHOCYTES, REH HAD VERY LOW CONSTITUTIVE AHR EXPRESSION THAT COULD BE ATTRIBUTED TO PROMOTER HYPERMETHYLATION SINCE TREATMENT WITH THE DNA DEMETHYLATING AGENT 5-AZA-2'-DEOXYCITIDINE (AZA) SIGNIFICANTLY INCREASED AHR MRNA AND PROTEIN. THESE RESULTS IN LEUKEMIA-DERIVED CELL LINES WERE FURTHER CONFIRMED IN PRIMARY ALL, WHERE 33% OF THE PATIENTS (7/21) HAD AHR PROMOTER HYPERMETHYLATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) SHOWED THAT METHYLATION IMPAIRED BINDING OF THE TRANSCRIPTION FACTOR SP1 TO THE AHR PROMOTER, THUS PROVIDING A MECHANISM FOR AHR DOWNREGULATION IN REH CELLS. THEREFORE, PROMOTER HYPERMETHYLATION REPRESENTS A NOVEL EPIGENETIC MECHANISM DOWNREGULATING AHR ACTIVITY IN HEMATOLOGICAL MALIGNANCIES SUCH AS ALL. 2006 9 4212 39 METHAMPHETAMINE DOWNREGULATES STRIATAL GLUTAMATE RECEPTORS VIA DIVERSE EPIGENETIC MECHANISMS. BACKGROUND: CHRONIC METHAMPHETAMINE (METH) EXPOSURE CAUSES NEUROADAPTATIONS AT GLUTAMATERGIC SYNAPSES. METHODS: TO IDENTIFY THE METH-INDUCED EPIGENETIC UNDERPINNINGS OF THESE NEUROADAPTATIONS, WE INJECTED INCREASING METH DOSES TO RATS FOR 2 WEEKS AND MEASURED STRIATAL GLUTAMATE RECEPTOR EXPRESSION. WE THEN QUANTIFIED THE EFFECTS OF METH EXPOSURE ON HISTONE ACETYLATION. WE ALSO MEASURED METH-INDUCED CHANGES IN DNA METHYLATION AND DNA HYDROXYMETHYLATION. RESULTS: CHRONIC METH DECREASED TRANSCRIPT AND PROTEIN EXPRESSION OF GLUA1 AND GLUA2 ALPHA-AMINO-3-HYDROXY-5-METHYL-4-ISOXAZOLE PROPIONIC ACID RECEPTOR (AMPAR) AND GLUN1 N-METHYL-D-ASPARTATE RECEPTOR SUBUNITS. THESE CHANGES WERE ASSOCIATED WITH ALTERED ELECTROPHYSIOLOGICAL GLUTAMATERGIC RESPONSES IN STRIATAL NEURONS. CHROMATIN IMMUNOPRECIPITATION-POLYMERASE CHAIN REACTION REVEALED THAT METH DECREASED ENRICHMENT OF ACETYLATED HISTONE H4 ON GLUA1, GLUA2, AND GLUN1 PROMOTERS. METHAMPHETAMINE EXPOSURE ALSO INCREASED REPRESSOR ELEMENT-1 SILENCING TRANSCRIPTION FACTOR (REST) COREPRESSOR 1, METHYLATED CPG BINDING PROTEIN 2, AND HISTONE DEACETYLASE 2 ENRICHMENT, BUT NOT OF SIRTUIN 1 OR SIRTUIN 2, ONTO GLUA1 AND GLUA2 GENE SEQUENCES. MOREOVER, METH CAUSED INTERACTIONS OF REST COREPRESSOR 1 AND METHYLATED CPG BINDING PROTEIN 2 WITH HISTONE DEACETYLASE 2 AND OF REST WITH HISTONE DEACETYLASE 1. SURPRISINGLY, METHYLATED DNA IMMUNOPRECIPITATION AND HYDROXYMETHYLATED DNA IMMUNOPRECIPITATION-POLYMERASE CHAIN REACTION REVEALED METH-INDUCED DECREASED ENRICHMENT OF 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE AT GLUA1 AND GLUA2 PROMOTER SEQUENCES. IMPORTANTLY, THE HISTONE DEACETYLASE INHIBITOR, VALPROIC ACID, BLOCKED METH-INDUCED DECREASED EXPRESSION OF AMPAR AND N-METHYL-D-ASPARTATE RECEPTOR SUBUNITS. FINALLY, VALPROIC ACID ALSO ATTENUATED METH-INDUCED DECREASE H4K16AC RECRUITMENT ON AMPAR GENE SEQUENCES. CONCLUSIONS: THESE OBSERVATIONS SUGGEST THAT HISTONE H4 HYPOACETYLATION MAY BE THE MAIN DETERMINANT OF METH-INDUCED DECREASED STRIATAL GLUTAMATE RECEPTOR EXPRESSION. 2014 10 1315 37 DELTA FOSB MEDIATES EPIGENETIC DESENSITIZATION OF THE C-FOS GENE AFTER CHRONIC AMPHETAMINE EXPOSURE. THE MOLECULAR MECHANISMS UNDERLYING THE TRANSITION FROM RECREATIONAL DRUG USE TO CHRONIC ADDICTION REMAIN POORLY UNDERSTOOD. ONE MOLECULE IMPLICATED IN THIS PROCESS IS DELTAFOSB, A TRANSCRIPTION FACTOR THAT ACCUMULATES IN STRIATUM AFTER REPEATED DRUG EXPOSURE AND MEDIATES SENSITIZED BEHAVIORAL RESPONSES TO PSYCHOSTIMULANTS AND OTHER DRUGS OF ABUSE. THE DOWNSTREAM TRANSCRIPTIONAL MECHANISMS BY WHICH DELTAFOSB REGULATES DRUG-INDUCED BEHAVIORS ARE INCOMPLETELY UNDERSTOOD. WE REPORTED PREVIOUSLY THE CHROMATIN REMODELING MECHANISMS BY WHICH DELTAFOSB ACTIVATES THE EXPRESSION OF CERTAIN GENES; HOWEVER, THE MECHANISMS UNDERLYING DELTAFOSB-MEDIATED GENE REPRESSION REMAIN UNKNOWN. HERE, WE IDENTIFY C-FOS, AN IMMEDIATE EARLY GENE RAPIDLY INDUCED IN STRIATUM AFTER ACUTE PSYCHOSTIMULANT EXPOSURE, AS A NOVEL DOWNSTREAM TARGET THAT IS REPRESSED CHRONICALLY BY DELTAFOSB. WE SHOW THAT ACCUMULATION OF DELTAFOSB IN STRIATUM AFTER CHRONIC AMPHETAMINE TREATMENT DESENSITIZES C-FOS MRNA INDUCTION TO A SUBSEQUENT DRUG DOSE. DELTAFOSB DESENSITIZES C-FOS EXPRESSION BY RECRUITING HISTONE DEACETYLASE 1 (HDAC1) TO THE C-FOS GENE PROMOTER, WHICH, IN TURN, DEACETYLATES SURROUNDING HISTONES AND ATTENUATES GENE ACTIVITY. ACCORDINGLY, LOCAL KNOCK-OUT OF HDAC1 IN STRIATUM ABOLISHES AMPHETAMINE-INDUCED DESENSITIZATION OF THE C-FOS GENE. IN CONCERT, CHRONIC AMPHETAMINE INCREASES HISTONE H3 METHYLATION ON THE C-FOS PROMOTER, A CHROMATIN MODIFICATION ALSO KNOWN TO REPRESS GENE ACTIVITY, AS WELL AS EXPRESSION LEVELS OF THE H3 HISTONE METHYLTRANSFERASE, KMT1A (LYSINE METHYLTRANSFERASE 1A, FORMERLY SUV39H1). THIS STUDY REVEALS A NOVEL EPIGENETIC PATHWAY THROUGH WHICH DELTAFOSB MEDIATES DISTINCT TRANSCRIPTIONAL PROGRAMS THAT MAY ULTIMATELY ALTER BEHAVIORAL PLASTICITY TO CHRONIC AMPHETAMINE EXPOSURE. 2008 11 917 43 CHRONIC HIGH-FAT DIET DRIVES POSTNATAL EPIGENETIC REGULATION OF MU-OPIOID RECEPTOR IN THE BRAIN. OPIOID SYSTEM DYSREGULATION HAS BEEN OBSERVED IN BOTH GENETIC AND HIGH-FAT DIET (HFD)-INDUCED MODELS OF OBESITY. AN UNDERSTANDING OF THE MOLECULAR MECHANISMS OF MOR TRANSCRIPTIONAL REGULATION, PARTICULARLY WITHIN AN IN VIVO CONTEXT, IS LACKING. USING A DIET-INDUCED MODEL OF OBESITY (DIO), MICE WERE FED A HIGH-FAT DIET (60% CALORIES FROM FAT) FROM WEANING TO >18 WEEKS OF AGE. COMPARED WITH MICE FED THE CONTROL DIET, DIO MICE HAD A DECREASED PREFERENCE FOR SUCROSE. MOR MRNA EXPRESSION WAS DECREASED IN REWARD-RELATED CIRCUITRY (VENTRAL TEGMENTAL AREA (VTA), NUCLEUS ACCUMBENS (NAC), AND PREFRONTAL CORTEX (PFC)) BUT NOT THE HYPOTHALAMUS, IMPORTANT IN THE HOMEOSTATIC REGULATION OF FEEDING. DNA METHYLATION IS AN EPIGENETIC MODIFICATION THAT LINKS ENVIRONMENTAL EXPOSURES TO ALTERED GENE EXPRESSION. WE FOUND A SIGNIFICANT INCREASE IN DNA METHYLATION IN THE MOR PROMOTER REGION WITHIN THE REWARD-RELATED BRAIN REGIONS. METHYL CPG-BINDING PROTEIN 2 (MECP2) CAN BIND METHYLATED DNA AND REPRESS TRANSCRIPTION, AND DIO MICE SHOWED INCREASED BINDING OF MECP2 TO THE MOR PROMOTER IN REWARD-RELATED REGIONS OF THE BRAIN. FINALLY, USING CHIP ASSAYS WE EXAMINED H3K9 METHYLATION (INACTIVE CHROMATIN) AND H3 ACETYLATION (ACTIVE CHROMATIN) WITHIN THE MOR PROMOTER REGION AND FOUND INCREASED H3K9 METHYLATION AND DECREASED H3 ACETYLATION. THESE DATA ARE THE FIRST TO IDENTIFY DNA METHYLATION, MECP2 RECRUITMENT, AND CHROMATIN REMODELING AS MECHANISMS LEADING TO TRANSCRIPTIONAL REPRESSION OF MOR IN THE BRAINS OF MICE FED A HIGH-FAT DIET. 2011 12 6660 40 UPREGULATION OF CXCR4 THROUGH PROMOTER DEMETHYLATION CONTRIBUTES TO INFLAMMATORY HYPERALGESIA IN RATS. AIM AND METHODS: CHRONIC PAIN ASSOCIATED WITH INFLAMMATION IS A COMMON CLINICAL PROBLEM, AND THE UNDERLYING MECHANISMS YET ARE INCOMPLETELY DEFINED. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER INFLAMMATORY PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE, WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR4 EXPRESSION IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO INFLAMMATORY PAIN INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA) IN RATS. RESULTS: INTRAPLANTAR INJECTION OF CFA COULD NOT ONLY INDUCE SIGNIFICANT HYPERALGESIA IN RATS, BUT ALSO SIGNIFICANTLY INCREASE THE EXPRESSION OF CXCR4 MRNA AND PROTEIN IN THE DORSAL ROOT GANGLION (DRG). INTRATHECAL INJECTION OF CXCR4 ANTAGONIST AMD3100 SIGNIFICANTLY RELIEVED HYPERALGESIA IN INFLAMMATORY RATS IN A TIME- AND DOSE-DEPENDENT MANNER. BISULFITE SEQUENCING AND METHYLATION-SPECIFIC PCR DEMONSTRATE THAT CFA INJECTION LED TO A SIGNIFICANT DEMETHYLATION OF CPG ISLAND AT CXCR4 GENE PROMOTER. CONSISTENTLY, THE EXPRESSION OF DNMT3B WAS SIGNIFICANTLY DOWNREGULATED AFTER CFA INJECTION. ONLINE SOFTWARE PREDICTION REVEALS THREE BINDING SITES OF P65 IN THE CPG ISLAND OF CXCR4 GENE PROMOTER, WHICH HAS CONFIRMED BY THE CHROMATIN IMMUNOPRECIPITATION ASSAY, CFA TREATMENT SIGNIFICANTLY INCREASES THE RECRUITMENT OF P65 TO CXCR4 GENE PROMOTER. INHIBITION OF NF-KB SIGNALING USING P65 INHIBITOR PYRROLIDINE DITHIOCARBAMATE SIGNIFICANTLY PREVENTED THE INCREASES OF THE CXCR4 EXPRESSION. CONCLUSION: UPREGULATION OF CXCR4 EXPRESSION DUE TO PROMOTER DEMETHYLATION FOLLOWED BY INCREASED RECRUITMENT OF P65 TO PROMOTER OF CXCR4 GENE CONTRIBUTES TO INFLAMMATORY HYPERALGESIA. THESE FINDINGS PROVIDE A THEORETICAL BASIS FOR THE TREATMENT OF CHRONIC PAIN FROM AN EPIGENETIC PERSPECTIVE. 2018 13 1320 33 DEMETHYLATION REGULATION OF BDNF GENE EXPRESSION IN DORSAL ROOT GANGLION NEURONS IS IMPLICATED IN OPIOID-INDUCED PAIN HYPERSENSITIVITY IN RATS. REPEATED ADMINISTRATION OF MORPHINE MAY RESULT IN OPIOID-INDUCED HYPERSENSITIVITY (OIH), WHICH INVOLVES ALTERED EXPRESSION OF NUMEROUS GENES, INCLUDING BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IN DORSAL ROOT GANGLION (DRG) NEURONS. YET, IT REMAINS UNCLEAR HOW BDNF EXPRESSION IS INCREASED IN DRG NEURONS AFTER REPEATED MORPHINE TREATMENT. DNA METHYLATION IS AN IMPORTANT MECHANISM OF EPIGENETIC CONTROL OF GENE EXPRESSION. IN THE CURRENT STUDY, WE HYPOTHESIZED THAT THE DEMETHYLATION REGULATION OF CERTAIN BDNF GENE PROMOTERS IN DRG NEURONS MAY CONTRIBUTE TO THE DEVELOPMENT OF OIH. REAL-TIME RT-PCR WAS USED TO ASSESS CHANGES IN THE MRNA TRANSCRIPTION LEVELS OF MAJOR BDNF EXONS INCLUDING EXON I, II, IV, VI, AS WELL AS TOTAL BDNF MRNA IN DRGS FROM RATS AFTER REPEATED MORPHINE ADMINISTRATION. THE LEVELS OF EXON IV AND TOTAL BDNF MRNA WERE SIGNIFICANTLY UPREGULATED BY REPEATED MORPHINE ADMINISTRATION, AS COMPARED TO THAT IN SALINE CONTROL GROUP. FURTHER, ELISA ARRAY AND IMMUNOCYTOCHEMISTRY STUDY REVEALED A ROBUST UPREGULATION OF BDNF PROTEIN EXPRESSION IN DRG NEURONS AFTER REPEATED MORPHINE EXPOSURE. CORRESPONDINGLY, THE METHYLATION LEVELS OF BDNF EXON IV PROMOTER SHOWED A SIGNIFICANT DOWNREGULATION BY MORPHINE TREATMENT. IMPORTANTLY, INTRATHECAL ADMINISTRATION OF A BDNF ANTIBODY, BUT NOT CONTROL IGG, SIGNIFICANTLY INHIBITED MECHANICAL HYPERSENSITIVITY THAT DEVELOPED IN RATS AFTER REPEATED MORPHINE TREATMENT. CONVERSELY, INTRATHECAL ADMINISTRATION OF AN INHIBITOR OF DNA METHYLATION, 5-AZA-2'-DEOXYCYTIDINE (5-AZA-DC) MARKEDLY UPREGULATED THE BDNF PROTEIN EXPRESSION IN DRG NEURONS AND ENHANCED THE MECHANICAL ALLODYNIA AFTER REPEATED MORPHINE EXPOSURE. TOGETHER, OUR FINDINGS SUGGEST THAT DEMETHYLATION REGULATION OF BDNF GENE PROMOTER MAY BE IMPLICATED IN THE DEVELOPMENT OF OIH THROUGH EPIGENETIC CONTROL OF BDNF EXPRESSION IN DRG NEURONS. 2016 14 3175 32 H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CHRONIC MYELOGENOUS LEUKEMIA CELLS INDUCED BY IMATINIB. INCREASING EVIDENCE SUGGESTS THAT HISTONE H2AX PLAYS A CRITICAL ROLE IN REGULATION OF TUMOR CELL APOPTOSIS AND ACTS AS A NOVEL HUMAN TUMOR SUPPRESSOR PROTEIN. HOWEVER, THE ACTION OF H2AX IN CHRONIC MYELOGENOUS LEUKEMIA (CML) CELLS IS UNKNOWN. THE DETAILED MECHANISM AND EPIGENETIC REGULATION BY H2AX REMAIN ELUSIVE IN CANCER CELLS. HERE, WE REPORT THAT H2AX WAS INVOLVED IN APOPTOSIS OF CML CELLS. OVEREXPRESSION OF H2AX INCREASED APOPTOTIC SENSITIVITY OF CML CELLS (K562) INDUCED BY IMATINIB. HOWEVER, OVEREXPRESSION OF SER139-MUTATED H2AX (BLOCKING PHOSPHORYLATION) DECREASED SENSITIVITY OF K562 CELLS TO APOPTOSIS. SIMILARLY, KNOCKDOWN OF H2AX MADE K562 CELLS RESISTANT TO APOPTOTIC INDUCTION. THESE RESULTS REVEALED THAT THE FUNCTION OF H2AX INVOLVED IN APOPTOSIS IS STRICTLY RELATED TO ITS PHOSPHORYLATION (SER139). OUR DATA FURTHER INDICATED THAT IMATINIB MAY STIMULATE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) FAMILY MEMBER P38, AND H2AX PHOSPHORYLATION FOLLOWED A SIMILAR TIME COURSE, SUGGESTING A PARALLEL RESPONSE. H2AX PHOSPHORYLATION CAN BE BLOCKED BY P38 SIRNA OR ITS INHIBITOR. THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION WAS REGULATED BY P38 MAPK PATHWAY IN K562 CELLS. HOWEVER, THE P38 MAPK DOWNSTREAM, MITOGEN- AND STRESS-ACTIVATED PROTEIN KINASE-1 AND -2, WHICH PHOSPHORYLATED HISTONE H3, WERE NOT REQUIRED FOR H2AX PHOSPHORYLATION DURING APOPTOSIS. FINALLY, WE PROVIDED EPIGENETIC EVIDENCE THAT H2AX PHOSPHORYLATION REGULATED APOPTOSIS-RELATED GENE BIM EXPRESSION. BLOCKING OF H2AX PHOSPHORYLATION INHIBITED BIM GENE EXPRESSION. TAKEN TOGETHER, THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CML CELLS INDUCED BY IMATINIB. 2014 15 3082 41 GENOME-WIDE REDISTRIBUTION OF MECP2 IN DORSAL ROOT GANGLIA AFTER PERIPHERAL NERVE INJURY. BACKGROUND: METHYL-CPG-BINDING PROTEIN 2 (MECP2), A PROTEIN WITH AFFINITY FOR METHYLATED CYTOSINES, IS CRUCIAL FOR NEURONAL DEVELOPMENT AND FUNCTION. MECP2 REGULATES GENE EXPRESSION THROUGH ACTIVATION, REPRESSION AND CHROMATIN REMODELING. MUTATIONS IN MECP2 CAUSE RETT SYNDROME, AND THESE PATIENTS DISPLAY IMPAIRED NOCICEPTION. WE OBSERVED AN INCREASE IN MECP2 EXPRESSION IN MOUSE DORSAL ROOT GANGLIA (DRG) AFTER PERIPHERAL NERVE INJURY. THE FUNCTIONAL IMPLICATION OF INCREASED MECP2 IS LARGELY UNKNOWN. TO IDENTIFY REGIONS OF THE GENOME BOUND BY MECP2 IN THE DRG AND THE CHANGES INDUCED BY NERVE INJURY, A CHROMATIN IMMUNOPRECIPITATION OF MECP2 FOLLOWED BY SEQUENCING (CHIP-SEQ) WAS PERFORMED 4 WEEKS AFTER SPARED NERVE INJURY (SNI). RESULTS: WHILE THE NUMBER OF BINDING SITES ACROSS THE GENOME REMAINED SIMILAR IN THE SNI MODEL AND SHAM CONTROL, SNI INDUCED THE REDISTRIBUTION OF MECP2 TO TRANSCRIPTIONALLY RELEVANT REGIONS. TO DETERMINE HOW DIFFERENTIAL BINDING OF MECP2 CAN AFFECT GENE EXPRESSION IN THE DRG, WE INVESTIGATED MMU-MIR-126, A MICRORNA LOCUS THAT HAD ENRICHED MECP2 BINDING IN THE SNI MODEL. ENRICHED MECP2 BINDING TO MIR-126 LOCUS AFTER NERVE INJURY REPRESSED MIR-126 EXPRESSION, AND THIS WAS NOT MEDIATED BY ALTERATIONS IN METHYLATION PATTERN AT THE MIR-126 LOCUS. DOWNREGULATION OF MIR-126 RESULTED IN THE UPREGULATION OF ITS TWO TARGET GENES DNMT1 AND VEGFA IN NEURO 2A CELLS AND IN SNI MODEL COMPARED TO CONTROL. THESE TARGET GENES WERE SIGNIFICANTLY DOWNREGULATED IN MECP2-NULL MICE COMPARED TO WILD-TYPE LITTERMATES, INDICATING A REGULATORY ROLE FOR MECP2 IN ACTIVATING DNMT1 AND VEGFA EXPRESSION. INTRATHECAL DELIVERY OF MIR-126 WAS NOT SUFFICIENT TO REVERSE NERVE INJURY-INDUCED MECHANICAL AND THERMAL HYPERSENSITIVITY, BUT DECREASED DNMT1 AND VEGFA EXPRESSION IN THE DRG. CONCLUSIONS: OUR STUDY SHOWS A REGULATORY ROLE FOR MECP2 IN THAT CHANGES IN GLOBAL REDISTRIBUTION CAN RESULT IN DIRECT AND INDIRECT MODULATION OF GENE EXPRESSION IN THE DRG. ALTERATIONS IN GENOME-WIDE BINDING OF MECP2 THEREFORE PROVIDE A MOLECULAR BASIS FOR A BETTER UNDERSTANDING OF EPIGENETIC REGULATION-INDUCED MOLECULAR CHANGES UNDERLYING NERVE INJURY. 2016 16 66 29 A KEY ROLE FOR EZH2 IN EPIGENETIC SILENCING OF HOX GENES IN MANTLE CELL LYMPHOMA. THE CHROMATIN MODIFIER EZH2 IS OVEREXPRESSED AND ASSOCIATED WITH INFERIOR OUTCOME IN MANTLE CELL LYMPHOMA (MCL). RECENTLY, WE DEMONSTRATED PREFERENTIAL DNA METHYLATION OF HOX GENES IN MCL COMPARED WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), DESPITE THESE GENES NOT BEING EXPRESSED IN EITHER ENTITY. SINCE EZH2 HAS BEEN SHOWN TO REGULATE HOX GENE EXPRESSION, TO GAIN FURTHER INSIGHT INTO ITS POSSIBLE ROLE IN DIFFERENTIAL SILENCING OF HOX GENES IN MCL VS. CLL, WE PERFORMED DETAILED EPIGENETIC CHARACTERIZATION USING REPRESENTATIVE CELL LINES AND PRIMARY SAMPLES. WE OBSERVED SIGNIFICANT OVEREXPRESSION OF EZH2 IN MCL VS. CLL. CHROMATIN IMMUNE PRECIPITATION (CHIP) ASSAYS REVEALED THAT EZH2 CATALYZED REPRESSIVE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3), WHICH WAS SUFFICIENT TO SILENCE HOX GENES IN CLL, WHEREAS IN MCL H3K27ME3 IS ACCOMPANIED BY DNA METHYLATION FOR A MORE STABLE REPRESSION. MORE IMPORTANTLY, HYPERMETHYLATION OF THE HOX GENES IN MCL RESULTED FROM EZH2 OVEREXPRESSION AND SUBSEQUENT RECRUITMENT OF THE DNA METHYLATION MACHINERY ONTO HOX GENE PROMOTERS. THE IMPORTANCE OF EZH2 UPREGULATION IN THIS PROCESS WAS FURTHER UNDERSCORED BY SIRNA TRANSFECTION AND EZH2 INHIBITOR EXPERIMENTS. ALTOGETHER, THESE OBSERVATIONS IMPLICATE EZH2 IN THE LONG-TERM SILENCING OF HOX GENES IN MCL, AND ALLUDE TO ITS POTENTIAL AS A THERAPEUTIC TARGET WITH CLINICAL IMPACT. 2013 17 6599 33 TWIST1 AND TWIST2 INDUCE HUMAN MACROPHAGE MEMORY UPON CHRONIC INNATE RECEPTOR TREATMENT BY HDAC-MEDIATED DEACETYLATION OF CYTOKINE PROMOTERS. INTESTINAL TISSUES ARE CONTINUOUSLY EXPOSED TO MICROBIAL PRODUCTS THAT STIMULATE PATTERN-RECOGNITION RECEPTORS (PRRS). ONGOING PRR STIMULATION CAN CONFER EPIGENETIC CHANGES IN MACROPHAGES, WHICH CAN THEN REGULATE SUBSEQUENT IMMUNE OUTCOMES AND ADAPTATION TO THE LOCAL ENVIRONMENT. MECHANISMS LEADING TO THESE CHANGES ARE INCOMPLETELY UNDERSTOOD. WE FOUND THAT SHORT-TERM STIMULATION OF THE PRR NOD2 IN PRIMARY HUMAN MONOCYTE-DERIVED MACROPHAGES RESULTED IN INCREASED H3 AND H4 ACETYLATION OF CYTOKINE PROMOTERS, CONSISTENT WITH THE INCREASED CYTOKINE SECRETION OBSERVED. HOWEVER, WITH PROLONGED NOD2 STIMULATION, BOTH THE ACETYLATION AND CYTOKINE SECRETION WERE DRAMATICALLY DECREASED. CHRONIC NOD2 STIMULATION UPREGULATED THE TRANSCRIPTION FACTORS TWIST1 AND TWIST2, WHICH BOUND TO THE PROMOTERS OF THE HISTONE DEACETYLASES HDAC1 AND HDAC3 AND INDUCED HDAC1 AND HDAC3 EXPRESSION. HDAC1 AND HDAC3 THEN MEDIATED HISTONE DEACETYLATION AT CYTOKINE PROMOTERS AND, IN TURN, CYTOKINE DOWNREGULATION UNDER THESE CONDITIONS. SIMILAR REGULATION WAS OBSERVED UPON CHRONIC STIMULATION OF MULTIPLE PRRS. CONSISTENT WITH THE CHRONIC MICROBIAL EXPOSURE IN THE INTESTINAL ENVIRONMENT, TWIST1, TWIST2, HDAC1, AND HDAC3 WERE UPREGULATED IN HUMAN INTESTINAL RELATIVE TO PERIPHERAL MACROPHAGES. IMPORTANTLY, COMPLEMENTING HDAC1 AND HDAC3 IN TWIST1/TWIST2-DEFICIENT MONOCYTE-DERIVED MACROPHAGES RESTORED THE REDUCED HISTONE ACETYLATION ON CYTOKINE PROMOTERS AND THE DECREASED CYTOKINE SECRETION WITH CHRONIC NOD2 STIMULATION. TAKEN TOGETHER, WE IDENTIFY MECHANISMS WHEREIN TWIST1 AND TWIST2 PROMOTE CHROMATIN MODIFICATIONS, RESULTING IN MACROPHAGE INSTRUCTION AND ADAPTATION TO CONDITIONS IN THE INTESTINAL MICROENVIRONMENT. 2019 18 1317 34 DELTAFOSB REGULATES GENE EXPRESSION AND COGNITIVE DYSFUNCTION IN A MOUSE MODEL OF ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS CHARACTERIZED BY COGNITIVE DECLINE AND 5- TO 10-FOLD INCREASED SEIZURE INCIDENCE. HOW SEIZURES CONTRIBUTE TO COGNITIVE DECLINE IN AD OR OTHER DISORDERS IS UNCLEAR. WE SHOW THAT SPONTANEOUS SEIZURES INCREASE EXPRESSION OF DELTAFOSB, A HIGHLY STABLE FOS-FAMILY TRANSCRIPTION FACTOR, IN THE HIPPOCAMPUS OF AN AD MOUSE MODEL. DELTAFOSB SUPPRESSED EXPRESSION OF THE IMMEDIATE EARLY GENE C-FOS, WHICH IS CRITICAL FOR PLASTICITY AND COGNITION, BY BINDING ITS PROMOTER AND TRIGGERING HISTONE DEACETYLATION. ACUTE HISTONE DEACETYLASE (HDAC) INHIBITION OR INHIBITION OF DELTAFOSB ACTIVITY RESTORED C-FOS INDUCTION AND IMPROVED COGNITION IN AD MICE. ADMINISTRATION OF SEIZURE-INDUCING AGENTS TO NONTRANSGENIC MICE ALSO RESULTED IN DELTAFOSB-MEDIATED SUPPRESSION OF C-FOS, SUGGESTING THAT THIS MECHANISM IS NOT CONFINED TO AD MICE. THESE RESULTS EXPLAIN OBSERVATIONS THAT C-FOS EXPRESSION INCREASES AFTER ACUTE NEURONAL ACTIVITY BUT DECREASES WITH CHRONIC ACTIVITY. MOREOVER, THESE RESULTS INDICATE A GENERAL MECHANISM BY WHICH SEIZURES CONTRIBUTE TO PERSISTENT COGNITIVE DEFICITS, EVEN DURING SEIZURE-FREE PERIODS. 2017 19 1656 31 DOUBLE STRAND BREAKS CAN INITIATE GENE SILENCING AND SIRT1-DEPENDENT ONSET OF DNA METHYLATION IN AN EXOGENOUS PROMOTER CPG ISLAND. CHRONIC EXPOSURE TO INDUCERS OF DNA BASE OXIDATION AND SINGLE AND DOUBLE STRAND BREAKS CONTRIBUTE TO TUMORIGENESIS. IN ADDITION TO THE GENETIC CHANGES CAUSED BY THIS DNA DAMAGE, SUCH TUMORS OFTEN CONTAIN EPIGENETICALLY SILENCED GENES WITH ABERRANT PROMOTER REGION CPG ISLAND DNA HYPERMETHYLATION. WE HEREIN EXPLORE THE RELATIONSHIPS BETWEEN SUCH DNA DAMAGE AND EPIGENETIC GENE SILENCING USING AN EXPERIMENTAL MODEL IN WHICH WE INDUCE A DEFINED DOUBLE STRAND BREAK IN AN EXOGENOUS PROMOTER CONSTRUCT OF THE E-CADHERIN CPG ISLAND, WHICH IS FREQUENTLY ABERRANTLY DNA HYPERMETHYLATED IN EPITHELIAL CANCERS. FOLLOWING THE ONSET OF REPAIR OF THE BREAK, WE OBSERVE RECRUITMENT TO THE SITE OF DAMAGE OF KEY PROTEINS INVOLVED IN ESTABLISHING AND MAINTAINING TRANSCRIPTIONAL REPRESSION, NAMELY SIRT1, EZH2, DNMT1, AND DNMT3B, AND THE APPEARANCE OF THE SILENCING HISTONE MODIFICATIONS, HYPOACETYL H4K16, H3K9ME2 AND ME3, AND H3K27ME3. ALTHOUGH IN MOST CELLS SELECTED AFTER THE BREAK, DNA REPAIR OCCURS FAITHFULLY WITH PRESERVATION OF ACTIVITY OF THE PROMOTER, A SMALL PERCENTAGE OF THE PLATED CELLS DEMONSTRATE INDUCTION OF HERITABLE SILENCING. THE CHROMATIN AROUND THE BREAK SITE IN SUCH A SILENT CLONE IS ENRICHED FOR MOST OF THE ABOVE SILENT CHROMATIN PROTEINS AND HISTONE MARKS, AND THE REGION HARBORS THE APPEARANCE OF INCREASING DNA METHYLATION IN THE CPG ISLAND OF THE PROMOTER. DURING THE ACUTE BREAK, SIRT1 APPEARS TO BE REQUIRED FOR THE TRANSIENT RECRUITMENT OF DNMT3B AND SUBSEQUENT METHYLATION OF THE PROMOTER IN THE SILENT CLONES. TAKEN TOGETHER, OUR DATA SUGGEST THAT NORMAL REPAIR OF A DNA BREAK CAN OCCASIONALLY CAUSE HERITABLE SILENCING OF A CPG ISLAND-CONTAINING PROMOTER BY RECRUITMENT OF PROTEINS INVOLVED IN SILENCING. FURTHERMORE, WITH CONTRIBUTION OF THE STRESS-RELATED PROTEIN SIRT1, THE BREAK CAN LEAD TO THE ONSET OF ABERRANT CPG ISLAND DNA METHYLATION, WHICH IS FREQUENTLY ASSOCIATED WITH TIGHT GENE SILENCING IN CANCER. 2008 20 1945 35 EPIGALLOCATECHIN-3-GALLATE, A HISTONE ACETYLTRANSFERASE INHIBITOR, INHIBITS EBV-INDUCED B LYMPHOCYTE TRANSFORMATION VIA SUPPRESSION OF RELA ACETYLATION. BECAUSE THE P300/CBP-MEDIATED HYPERACETYLATION OF RELA (P65) IS CRITICAL FOR NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) ACTIVATION, THE ATTENUATION OF P65 ACETYLATION IS A POTENTIAL MOLECULAR TARGET FOR THE PREVENTION OF CHRONIC INFLAMMATION. DURING OUR ONGOING SCREENING STUDY TO IDENTIFY NATURAL COMPOUNDS WITH HISTONE ACETYLTRANSFERASE INHIBITOR (HATI) ACTIVITY, WE IDENTIFIED EPIGALLOCATECHIN-3-GALLATE (EGCG) AS A NOVEL HATI WITH GLOBAL SPECIFICITY FOR THE MAJORITY OF HAT ENZYMES BUT WITH NO ACTIVITY TOWARD EPIGENETIC ENZYMES INCLUDING HDAC, SIRT1, AND HMTASE. AT A DOSE OF 100 MICROMOL/L, EGCG ABROGATES P300-INDUCED P65 ACETYLATION IN VITRO AND IN VIVO, INCREASES THE LEVEL OF CYTOSOLIC IKAPPABALPHA, AND SUPPRESSES TUMOR NECROSIS FACTOR ALPHA (TNFALPHA)-INDUCED NF-KAPPAB ACTIVATION. WE ALSO SHOWED THAT EGCG PREVENTS TNFALPHA-INDUCED P65 TRANSLOCATION TO THE NUCLEUS, CONFIRMING THAT HYPERACETYLATION IS CRITICAL FOR NF-KAPPAB TRANSLOCATION AS WELL AS ACTIVITY. FURTHERMORE, EGCG TREATMENT INHIBITED THE ACETYLATION OF P65 AND THE EXPRESSION OF NF-KAPPAB TARGET GENES IN RESPONSE TO DIVERSE STIMULI. FINALLY, EGCG REDUCED THE BINDING OF P300 TO THE PROMOTER REGION OF INTERLEUKIN-6 GENE WITH AN INCREASED RECRUITMENT OF HDAC3, WHICH HIGHLIGHTS THE IMPORTANCE OF THE BALANCE BETWEEN HATS AND HISTONE DEACETYLASES IN THE NF-KAPPAB-MEDIATED INFLAMMATORY SIGNALING PATHWAY. IMPORTANTLY, EGCG AT 50 MICROMOL/L DOSE COMPLETELY BLOCKS EBV INFECTION-INDUCED CYTOKINE EXPRESSION AND SUBSEQUENTLY THE EBV-INDUCED B LYMPHOCYTE TRANSFORMATION. THESE RESULTS SHOW THE CRUCIAL ROLE OF ACETYLATION IN THE DEVELOPMENT OF INFLAMMATORY-RELATED DISEASES. 2009