1 267 138 AFFECTIVE AND COGNITIVE BEHAVIOR IN THE ALPHA-GALACTOSIDASE A DEFICIENT MOUSE MODEL OF FABRY DISEASE. FABRY DISEASE IS AN X-LINKED INHERITED LYSOSOMAL STORAGE DISORDER WITH INTRACELLULAR ACCUMULATION OF GLOBOTRIAOSYLCERAMIDE (GB3) DUE TO ALPHA-GALACTOSIDASE A (ALPHA-GAL A) DEFICIENCY. FABRY PATIENTS FREQUENTLY REPORT OF ANXIETY, DEPRESSION, AND IMPAIRED COGNITIVE FUNCTION. WE CHARACTERIZED AFFECTIVE AND COGNITIVE PHENOTYPE OF MALE MICE WITH ALPHA-GAL A DEFICIENCY (FABRY KO) AND COMPARED RESULTS WITH THOSE OF AGE-MATCHED MALE WILDTYPE (WT) LITTERMATES. YOUNG (3 MONTHS) AND OLD (>/= 18 MONTHS) MICE WERE TESTED IN THE NAIVE STATE AND AFTER I.PL. INJECTION OF COMPLETE FREUND;S ADJUVANT (CFA) AS AN INFLAMMATORY PAIN MODEL. WE USED THE ELEVATED PLUS MAZE (EPM), THE LIGHT-DARK BOX (LDB) AND THE OPEN FIELD TEST (OF) TO INVESTIGATE ANXIETY-LIKE BEHAVIOR. THE FORCED SWIM TEST (FST) AND MORRIS WATER MAZE (MWM) WERE APPLIED TO ASSESS DEPRESSIVE-LIKE AND LEARNING BEHAVIOR. THE EPM TEST REVEALED NO INTERGROUP DIFFERENCE FOR ANXIETY-LIKE BEHAVIOR IN NAIVE YOUNG AND OLD FABRY KO MICE COMPARED TO WT LITTERMATES, EXCEPT FOR LONGER TIME SPENT IN OPEN ARMS OF THE EPM FOR YOUNG WT MICE COMPARED TO YOUNG FABRY KO MICE (P<0.05). AFTER CFA INJECTION, YOUNG FABRY KO MICE SHOWED INCREASED ANXIETY-LIKE BEHAVIOR COMPARED TO YOUNG WT LITTERMATES (P<0.05) AND NAIVE YOUNG FABRY KO MICE (P<0.05) IN THE EPM AS REFLECTED BY SHORTER TIME SPENT IN EPM OPEN ARMS. THERE WERE NO RELEVANT DIFFERENCES IN THE LDB AND THE OF TEST, EXCEPT FOR LONGER TIME SPENT IN THE CENTER ZONE OF THE OF BY YOUNG WT MICE COMPARED TO YOUNG FABRY KO MICE (P<0.05). COMPLEMENTARY TO THIS, DEPRESSION-LIKE AND LEARNING BEHAVIOR WERE NOT DIFFERENT BETWEEN GENOTYPES AND AGE-GROUPS, EXCEPT FOR THE EXPECTEDLY LOWER MEMORY PERFORMANCE IN OLDER AGE-GROUPS COMPARED TO YOUNG MICE. OUR RESULTS INDICATE THAT GENETIC INFLUENCES ON AFFECTIVE AND COGNITIVE SYMPTOMS IN FD MAY BE OF SUBORDINATE RELEVANCE, DRAWING ATTENTION TO POTENTIAL INFLUENCES OF ENVIRONMENTAL AND EPIGENETIC FACTORS. 2017 2 3082 33 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 3 1690 21 DUAL ROLES OF CHROMATIN REMODELING PROTEIN BRG1 IN ANGIOTENSIN II-INDUCED ENDOTHELIAL-MESENCHYMAL TRANSITION. ENDOTHELIAL-MESENCHYMAL TRANSITION (ENDMT) IS CONSIDERED ONE OF THE PROCESSES UNDERLYING TISSUE FIBROSIS BY CONTRIBUTING TO THE POOL OF MYOFIBROBLASTS. IN THE PRESENT STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISM WHEREBY ANGIOTENSIN II (ANG II) REGULATES ENDMT TO PROMOTE CARDIAC FIBROSIS FOCUSING ON THE ROLE OF CHROMATIN REMODELING PROTEIN BRG1. BRG1 KNOCKDOWN OR INHIBITION ATTENUATED ANG II-INDUCED ENDMT, AS EVIDENCED BY DOWN-REGULATION OF CDH5, AN ENDOTHELIAL MARKER, AND UP-REGULATION OF COL1A2, A MESENCHYMAL MARKER, IN CULTURED VASCULAR ENDOTHELIAL CELLS. ON THE ONE HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SP1 TO THE SNAI2 (ENCODING SLUG) PROMOTER TO ACTIVATE SNAI2 TRANSCRIPTION IN RESPONSE TO ANG II STIMULATION. ONCE ACTIVATED, SLUG BOUND TO THE CDH5 PROMOTER TO REPRESS CDH5 TRANSCRIPTION. ON THE OTHER HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SRF TO THE COL1A2 PROMOTER TO ACTIVATE COL1A2 TRANSCRIPTION. MECHANISTICALLY, BRG1 EVICTED HISTONES FROM THE TARGET PROMOTERS TO FACILITATE THE BINDINGS OF SP1 AND SRF. FINALLY, ENDOTHELIAL CONDITIONAL BRG1 KNOCKOUT MICE (CKO) EXHIBITED A REDUCTION IN CARDIAC FIBROSIS, COMPARED TO THE WILD TYPE (WT) LITTERMATES, IN RESPONSE TO CHRONIC ANG II INFUSION. IN CONCLUSION, OUR DATA DEMONSTRATE THAT BRG1 IS A KEY TRANSCRIPTIONAL COORDINATOR PROGRAMMING ANG II-INDUCED ENDMT TO CONTRIBUTE TO CARDIAC FIBROSIS. 2020 4 4603 28 NEGATIVE ALLOSTERIC MODULATION OF MGLUR5 PARTIALLY CORRECTS PATHOPHYSIOLOGY IN A MOUSE MODEL OF RETT SYNDROME. RETT SYNDROME (RTT) IS CAUSED BY MUTATIONS IN THE GENE ENCODING METHYL-CPG BINDING PROTEIN 2 (MECP2), AN EPIGENETIC REGULATOR OF MRNA TRANSCRIPTION. HERE, WE REPORT A TEST OF THE HYPOTHESIS OF SHARED PATHOPHYSIOLOGY OF RTT AND FRAGILE X, ANOTHER MONOGENIC CAUSE OF AUTISM AND INTELLECTUAL DISABILITY. IN FRAGILE X, THE LOSS OF THE MRNA TRANSLATIONAL REPRESSOR FMRP LEADS TO EXAGGERATED PROTEIN SYNTHESIS DOWNSTREAM OF METABOTROPIC GLUTAMATE RECEPTOR 5 (MGLUR5). WE FOUND THAT MGLUR5- AND PROTEIN-SYNTHESIS-DEPENDENT SYNAPTIC PLASTICITY WERE SIMILARLY ALTERED IN AREA CA1 OF MECP2 KO MICE. CA1 PYRAMIDAL CELL-TYPE-SPECIFIC, GENOME-WIDE PROFILING OF RIBOSOME-BOUND MRNAS WAS PERFORMED IN WILD-TYPE AND MECP2 KO HIPPOCAMPAL CA1 NEURONS TO REVEAL THE MECP2-REGULATED "TRANSLATOME." WE FOUND SIGNIFICANT OVERLAP BETWEEN RIBOSOME-BOUND TRANSCRIPTS OVEREXPRESSED IN THE MECP2 KO AND FMRP MRNA TARGETS. THESE TENDED TO ENCODE LONG GENES THAT WERE FUNCTIONALLY RELATED TO EITHER CYTOSKELETON ORGANIZATION OR THE DEVELOPMENT OF NEURONAL CONNECTIVITY. IN THE FMR1 KO MOUSE, CHRONIC TREATMENT WITH MGLUR5-NEGATIVE ALLOSTERIC MODULATORS (NAMS) HAS BEEN SHOWN TO AMELIORATE MANY MUTANT PHENOTYPES BY CORRECTING EXCESSIVE PROTEIN SYNTHESIS. IN MECP2 KO MICE, WE FOUND THAT MGLUR5 NAM TREATMENT SIGNIFICANTLY REDUCED THE LEVEL OF OVEREXPRESSED RIBOSOME-ASSOCIATED TRANSCRIPTS, PARTICULARLY THOSE THAT WERE ALSO FMRP TARGETS. SOME RETT PHENOTYPES WERE ALSO AMELIORATED BY TREATMENT, MOST NOTABLY HIPPOCAMPAL CELL SIZE AND LIFESPAN. TOGETHER, THESE RESULTS SUGGEST A POTENTIAL MECHANISTIC LINK BETWEEN MECP2-MEDIATED TRANSCRIPTION REGULATION AND MGLUR5/FMRP-MEDIATED PROTEIN TRANSLATION REGULATION THROUGH COREGULATION OF A SUBSET OF GENES RELEVANT TO SYNAPTIC FUNCTIONS. SIGNIFICANCE STATEMENT: ALTERED REGULATION OF SYNAPTIC PROTEIN SYNTHESIS HAS BEEN HYPOTHESIZED TO CONTRIBUTE TO THE PATHOPHYSIOLOGY THAT UNDERLIES MULTIPLE FORMS OF INTELLECTUAL DISABILITY AND AUTISM SPECTRUM DISORDER. HERE, WE SHOW IN A MOUSE MODEL OF RETT SYNDROME (MECP2 KO) THAT METABOTROPIC GLUTAMATE RECEPTOR 5 (MGLUR5)- AND PROTEIN-SYNTHESIS-DEPENDENT SYNAPTIC PLASTICITY ARE ABNORMAL IN THE HIPPOCAMPUS. WE FOUND THAT A SUBSET OF RIBOSOME-BOUND MRNAS WAS ABERRANTLY UPREGULATED IN HIPPOCAMPAL CA1 NEURONS OF MECP2 KO MICE, THAT THESE SIGNIFICANTLY OVERLAPPED WITH FMRP DIRECT TARGETS AND/OR SFARI HUMAN AUTISM GENES, AND THAT CHRONIC TREATMENT OF MECP2 KO MICE WITH AN MGLUR5-NEGATIVE ALLOSTERIC MODULATOR TUNES DOWN UPREGULATED RIBOSOME-BOUND MRNAS AND PARTIALLY IMPROVES MUTANT MICE PHENOTYPES. 2016 5 4161 24 MECP2 REGULATES ETHANOL SENSITIVITY AND INTAKE. WE HAVE INVESTIGATED THE EXPRESSION OF CHROMATIN-REGULATING GENES IN THE PREFRONTAL CORTEX AND IN THE SHELL SUBDIVISION OF THE NUCLEUS ACCUMBENS DURING PROTRACTED WITHDRAWAL IN MICE WITH INCREASED ETHANOL DRINKING AFTER CHRONIC INTERMITTENT ETHANOL (CIE) VAPOR EXPOSURE AND IN MICE WITH A HISTORY OF NON-DEPENDENT DRINKING. WE OBSERVED THAT THE METHYL-CPG BINDING PROTEIN 2 (MECP2) WAS ONE OF THE FEW CHROMATIN-REGULATING GENES TO BE DIFFERENTIALLY REGULATED BY A HISTORY OF DEPENDENCE. AS MECP2 HAS THE POTENTIAL OF ACTING AS A BROAD GENE REGULATOR, WE INVESTIGATED SENSITIVITY TO ETHANOL AND ETHANOL DRINKING IN MECP2(308/) (Y) MICE, WHICH HARBOR A TRUNCATED MECP2 ALLELE BUT HAVE A MILDER PHENOTYPE THAN MECP2 NULL MICE. WE OBSERVED THAT MECP2(308/) (Y) MICE WERE MORE SENSITIVE TO ETHANOL'S STIMULATORY AND SEDATIVE EFFECTS THAN WILD-TYPE (WT) MICE, DRANK LESS ETHANOL IN A LIMITED ACCESS 2 BOTTLE CHOICE PARADIGM AND DID NOT SHOW INCREASED DRINKING AFTER INDUCTION OF DEPENDENCE WITH EXPOSURE TO CIE VAPORS. ALCOHOL METABOLISM DID NOT DIFFER IN MECP2(308/) (Y) AND WT MICE. ADDITIONALLY, MECP2(308/) (Y) MICE DID NOT DIFFER FROM WT MICE IN ETHANOL PREFERENCE IN A 24-HOUR PARADIGM NOR IN THEIR INTAKE OF GRADED SOLUTIONS OF SACCHARIN OR QUININE, SUGGESTING THAT THE MECP2(308/) (Y) MUTATION DID NOT ALTER TASTE FUNCTION. LASTLY, USING THE GENE SET ENRICHMENT ANALYSIS ALGORITHM, WE FOUND A SIGNIFICANT OVERLAP IN THE GENES REGULATED BY ALCOHOL AND BY MECP2. TOGETHER, THESE RESULTS SUGGEST THAT MECP2 CONTRIBUTES TO THE REGULATION OF ETHANOL SENSITIVITY AND DRINKING. 2014 6 3177 37 H3K9ME2 REGULATION OF BDNF EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX IS INVOLVED IN THE DEPRESSIVE-LIKE PHENOTYPE INDUCED BY MATERNAL SEPARATION IN MALE RATS. BACKGROUND: EARLY LIFE STRESS (ELS) INDUCES A DEPRESSIVE-LIKE PHENOTYPE AND INCREASES THE RISK OF DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN CONFIRMED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSION. HOWEVER, THE MECHANISM BY WHICH ELS ALTERS THE EPIGENETIC REGULATION OF BDNF AND CHANGES SUSCEPTIBILITY TO DEPRESSION HAS NOT BEEN FULLY CLARIFIED. METHODS: THE PRESENT STUDY USED MATERNAL SEPARATION (MS) AND CHRONIC UNPREDICTED MILD STRESS (CUMS) TO ESTABLISH AN MS ANIMAL MODEL AND A DEPRESSIVE ANIMAL MODEL. WE ASSESSED DEPRESSIVE-LIKE BEHAVIOURS, INCLUDING ANHEDONIA, LOCOMOTOR ACTIVITY, ANXIETY-LIKE BEHAVIOUR, AND SPATIAL MEMORY, USING THE SUCROSE PREFERENCE TEST, THE OPEN FIELD TEST, THE ELEVATED PLUS MAZE TEST, AND THE MORRIS WATER MAZE TEST. WE ALSO INVESTIGATED BDNF AND H3K9ME2 EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX (MPFC) BY IMMUNOHISTOCHEMISTRY, WESTERN BLOTTING, AND QPCR ANALYSIS. ADDITIONALLY, WE USED UNC0642, A SMALL MOLECULE INHIBITOR OF HISTONE METHYLTRANSFERASE (G9A), AS AN INTERVENTION. RESULTS: THE RESULTS SHOWED THAT CUMS INDUCED DEPRESSIVE-LIKE BEHAVIOURS IN RATS AND RESULTED IN INCREASED H3K9ME2 EXPRESSION AND DECREASED BDNF EXPRESSION IN THE HIPPOCAMPUS AND MPFC. MORE IMPORTANTLY, ADULT MS RATS EXPERIENCING CUMS HAD MORE SEVERE DEPRESSIVE BEHAVIOURS, HAD HIGHER EXPRESSION OF H3K9ME2 IN THE HIPPOCAMPUS AND MPFC, AND HAD LOWER EXPRESSION OF BDNF IN THE HIPPOCAMPUS AND MPFC. IN ADDITION, ADMINISTRATION OF THE G9A INHIBITOR REVERSED MOST OF THE CHANGES. CONCLUSIONS: OUR STUDY SUGGESTS THAT ELS CHANGED BDNF AND H3K9ME2 EXPRESSION IN THE RAT BRAIN, RESULTING IN A DEPRESSIVE-LIKE PHENOTYPE. 2021 7 1320 26 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 8 2243 24 EPIGENETIC MODULATION OF CHRONIC ANXIETY AND PAIN BY HISTONE DEACETYLATION. PROLONGED EXPOSURE OF THE CENTRAL AMYGDALA (CEA) TO ELEVATED CORTICOSTEROIDS (CORT) FACILITATES LONG-TERM ANXIETY AND PAIN THROUGH ACTIVATION OF GLUCOCORTICOID RECEPTORS (GRS) AND CORTICOTROPIN-RELEASING FACTOR (CRF). HOWEVER, THE MECHANISMS MAINTAINING THESE RESPONSES ARE UNKNOWN. SINCE CHRONIC PHENOTYPES CAN BE SUSTAINED BY EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS SUCH AS DEACETYLATION, WE TESTED THE HYPOTHESIS THAT HISTONE DEACETYLATION CONTRIBUTES TO THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN INDUCED BY PROLONGED EXPOSURE OF THE CEA TO CORT. WE FOUND THAT BILATERAL INFUSIONS OF A HISTONE DEACETYLASE INHIBITOR INTO THE CEA ATTENUATED ANXIETY-LIKE BEHAVIOR AS WELL AS SOMATIC AND VISCERAL HYPERSENSITIVITY RESULTING FROM ELEVATED CORT EXPOSURE. MOREOVER, WE DELINEATED A NOVEL PATHWAY THROUGH WHICH HISTONE DEACETYLATION COULD CONTRIBUTE TO CORT REGULATION OF GR AND SUBSEQUENT CRF EXPRESSION IN THE CEA. SPECIFICALLY, DEACETYLATION OF HISTONE 3 AT LYSINE 9 (H3K9), THROUGH THE COORDINATED ACTION OF THE NAD+-DEPENDENT PROTEIN DEACETYLASE SIRTUIN-6 (SIRT6) AND NUCLEAR FACTOR KAPPA B (NFKAPPAB), SEQUESTERS GR EXPRESSION LEADING TO DISINHIBITION OF CRF. OUR RESULTS INDICATE THAT EPIGENETIC PROGRAMMING IN THE AMYGDALA, SPECIFICALLY HISTONE MODIFICATIONS, IS IMPORTANT IN THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN. 2015 9 4163 24 MECP2 REPRESSION OF G9A IN REGULATION OF PAIN AND MORPHINE REWARD. OPIOIDS ARE COMMONLY USED FOR PAIN RELIEF, BUT THEIR STRONG REWARDING EFFECTS DRIVE OPIOID MISUSE AND ABUSE. HOW PAIN AFFECTS THE LIABILITY OF OPIOID ABUSE IS UNKNOWN AT PRESENT. IN THIS STUDY, WE IDENTIFIED AN EPIGENETIC REGULATING CASCADE ACTIVATED BY BOTH PAIN AND THE OPIOID MORPHINE. BOTH PERSISTENT PAIN AND REPEATED MORPHINE UPREGULATED THE TRANSCRIPTIONAL REGULATOR MECP2 IN MOUSE CENTRAL NUCLEUS OF THE AMYGDALA (CEA). CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT MECP2 BOUND TO AND REPRESSED THE TRANSCRIPTIONAL REPRESSOR HISTONE DIMETHYLTRANSFERASE G9A, REDUCING G9A-CATALYZED REPRESSIVE MARK H3K9ME2 IN CEA. REPRESSION OF G9A ACTIVITY INCREASED EXPRESSION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF). BEHAVIORALLY, PERSISTENT INFLAMMATORY PAIN INCREASED THE SENSITIVITY TO ACQUIRING MORPHINE-INDUCED, REWARD-RELATED BEHAVIOR OF CONDITIONED PLACE PREFERENCE IN MICE. LOCAL VIRAL VECTOR-MEDIATED MECP2 OVEREXPRESSION, CRE-INDUCED G9A KNOCKDOWN, AND CEA APPLICATION OF BDNF MIMICKED, WHEREAS MECP2 KNOCKDOWN INHIBITED, THE PAIN EFFECT. THESE RESULTS SUGGEST THAT MECP2 DIRECTLY REPRESSES G9A AS A SHARED MECHANISM IN CENTRAL AMYGDALA FOR REGULATION OF EMOTIONAL RESPONSES TO PAIN AND OPIOID REWARD, AND FOR THEIR BEHAVIORAL INTERACTION. 2014 10 917 24 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 11 6388 33 THE ROLE OF SIRT1 IN THE BASOLATERAL AMYGDALA IN DEPRESSION-LIKE BEHAVIORS IN MICE. PREVIOUS INVESTIGATIONS HAVE IMPLICATED THE BASOLATERAL AMYGDALA (BLA) EPIGENETIC MECHANISMS IN THE PATHOPHYSIOLOGY OF DEPRESSION. SIRT1 IS A NAD+-DEPENDENT CLASS III HISTONE DEACETYLASE, WIDELY EXPRESSES IN BLA. HOWEVER, EPIGENETIC MECHANISMS IN THE BLA UNDER THE REGULATION OF SIRT1 IN THE DEPRESSION ARE LARGELY UNCHARACTERIZED. UNDER THE CHRONIC UNPREDICTABLE CHRONIC MILD STRESS (CUMS) MOUSE MODEL, WE USED ADENO-ASSOCIATED VIRAL VECTORS (AAV) THAT ENCODED SIRT1-SHRNA OR SIRT1 TO SPECIFICALLY KNOCKDOWN OR OVEREXPRESS SIRT1 IN BLA NEURONS, RESPECTIVELY. CUMS PROCEDURE INDUCED SIGNIFICANT DEPRESSION SYMPTOMS INCLUDING THE DECREASED SUCROSE PREFERENCE, THE LESS BODYWEIGHT GAINED, THE DECREASED IMMOBILE LATENCY AND THE INCREASED IMMOBILE TIME BOTH IN FORCED SWIM TEST (FST) AND TAIL SUSPENSION TEST (TST). KNOCKDOWN OF SIRT1 IN BLA GLUTAMATERGIC NEURONS REVERSED THESE DEPRESSION-LIKE BEHAVIORS AND RESTORED THE SYNAPTIC ABNORMALITIES. OVEREXPRESSION OF SIRT1 IN BLA GLUTAMATERGIC NEURONS INDUCED DEPRESSION-LIKE BEHAVIORS IN NON-STRESSED CONTROL MICE. THE RESULT OF PROTEIN EXPRESSIONS AND ULTRASTRUCTURAL CHANGES WERE CONSISTENT WITH THE BEHAVIORAL RESULTS. OUR STUDY SUGGESTED THAT DOWNREGULATION OF SIRT1 IN BLA HAS CERTAIN BENEFICIAL EFFECT ON CUMS-INDUCED DEPRESSION-LIKE BEHAVIORS SUCH AS ANOREXIA, ANHEDONIA, HOPELESSNESS AND DESPAIR. IN ADDITION, THE INCREASED EXPRESSION OF SIRT1 MAY BE THE IMMEDIATE CAUSE OF DEPRESSIVE-LIKE SYMPTOMS. THE ABNORMAL EXPRESSION OF SIRT1 MAY AFFECT THE TRANSCRIPTIONAL REGULATION MECHANISM AND SIGNALING PROTEIN ACETYLATION, AFFECTING NEUROPLASTICITY AND ULTIMATELY CONTRIBUTE TO MDD. IN THE STRESS-SUSCEPTIBLE MICE, THESE TWO MECHANISMS MAY CO-EXIST, BUT THE SPECIFIC MECHANISM NEEDS FURTHER RESEARCH. 2021 12 2300 23 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 13 3590 34 IMPAIRED LATENT INHIBITION IN GDNF-DEFICIENT MICE EXPOSED TO CHRONIC STRESS. INCREASED REACTIVITY TO STRESS IS MALADAPTIVE AND LINKED TO ABNORMAL BEHAVIORS AND PSYCHOPATHOLOGY. CHRONIC UNPREDICTABLE STRESS (CUS) ALTERS CATECHOLAMINERGIC NEUROTRANSMISSION AND REMODELS NEURONAL CIRCUITS INVOLVED IN LEARNING, ATTENTION AND DECISION MAKING. GLIAL-DERIVED NEUROTROPHIC FACTOR (GDNF) IS ESSENTIAL FOR THE PHYSIOLOGY AND SURVIVAL OF DOPAMINERGIC NEURONS IN SUBSTANTIA NIGRA AND OF NORADRENERGIC NEURONS IN THE LOCUS COERULEUS. UP-REGULATION OF GDNF EXPRESSION DURING STRESS IS LINKED TO RESILIENCE; ON THE OTHER HAND, THE INABILITY TO UP-REGULATE GDNF IN RESPONSE TO STRESS, AS A RESULT OF EITHER GENETIC OR EPIGENETIC MODIFICATIONS, INDUCES BEHAVIORAL ALTERATIONS. FOR EXAMPLE, GDNF-DEFICIENT MICE EXPOSED TO CHRONIC STRESS EXHIBIT ALTERATIONS OF EXECUTIVE FUNCTION, SUCH AS INCREASED TEMPORAL DISCOUNTING. HERE WE INVESTIGATED THE EFFECTS OF CUS ON LATENT INHIBITION (LI), A MEASURE OF SELECTIVE ATTENTION AND LEARNING, IN GDNF-HETEROZYGOUS (HET) MICE AND THEIR WILD-TYPE (WT) LITTERMATE CONTROLS. NO DIFFERENCES IN LI WERE FOUND BETWEEN GDNF HET AND WT MICE UNDER BASELINE EXPERIMENTAL CONDITIONS. HOWEVER, FOLLOWING CUS, GDNF-DEFICIENT MICE FAILED TO EXPRESS LI. MOREOVER, STRESSED GDNF-HET MICE, BUT NOT THEIR WT CONTROLS, SHOWED DECREASED NEURONAL ACTIVATION (NUMBER OF C-FOS POSITIVE NEURONS) IN THE NUCLEUS ACCUMBENS SHELL AND INCREASED ACTIVATION IN THE NUCLEUS ACCUMBENS CORE, BOTH KEY REGIONS IN THE EXPRESSION OF LI. OUR RESULTS ADD LI TO THE LIST OF BEHAVIORS AFFECTED BY CHRONIC STRESS AND SUPPORT A ROLE FOR GDNF DEFICITS IN STRESS-INDUCED PATHOLOGICAL BEHAVIORS RELEVANT TO SCHIZOPHRENIA AND OTHER PSYCHIATRIC DISORDERS. 2017 14 431 29 ANTIDEPRESSANT ADMINISTRATION MODULATES STRESS-INDUCED DNA METHYLATION AND DNA METHYLTRANSFERASE EXPRESSION IN RAT PREFRONTAL CORTEX AND HIPPOCAMPUS. STRESS AND ANTIDEPRESSANT TREATMENT CAN MODULATE DNA METHYLATION IN PROMOTER REGION OF GENES RELATED TO NEUROPLASTICITY AND MOOD REGULATION, THUS IMPLICATING THIS EPIGENETIC MECHANISM IN DEPRESSION NEUROBIOLOGY AND TREATMENT. ACCORDINGLY, SYSTEMIC ADMINISTRATION OF DNA METHYLTRANSFERASE (DNMT) INHIBITORS INDUCES ANTIDEPRESSANT-LIKE EFFECTS IN RODENTS. DNA METHYLATION IS CONVEYED BY DNMT 1, 3A AND 3B ISOFORMS, WHICH ARE DIFFERENTIALLY EXPRESSED IN THE BRAIN. IN ORDER TO INVESTIGATE IF THE BEHAVIORAL EFFECTS OF ANTIDEPRESSANTS COULD BE ASSOCIATED WITH CHANGES IN DNA METHYLATION AND DNMT EXPRESSION, WE INVESTIGATED THE EFFECTS INDUCED BY ACUTE AND REPEATED ANTIDEPRESSANT TREATMENT ON DNA METHYLATION AND DNMT EXPRESSION (1, 3A AND 3B ISOFORMS) IN DIFFERENT BRAIN REGIONS OF RATS EXPOSED TO A STRESS MODEL OF DEPRESSION, THE LEARNED HELPLESSNESS (LH). THEREFORE, RATS WERE EXPOSED TO PRETEST AND TREATED WITH ONE OR SEVEN INJECTIONS OF VEHICLE OR IMIPRAMINE (15 MG KG(-1)), WITH TEST SESSION PERFORMED ONE HOUR AFTER THE LAST INJECTION. CHRONIC, BUT NOT ACUTE, IMIPRAMINE ADMINISTRATION ATTENUATED ESCAPE FAILURES DURING THE TEST, A WELL DESCRIBED ANTIDEPRESSANT-LIKE EFFECT IN THIS MODEL. DNA METHYLATION AND DNMT (1, 3A AND 3B) LEVELS WERE MEASURED IN THE DORSAL AND VENTRAL HIPPOCAMPUS (DHPC, VHPC) AND IN THE PREFRONTAL CORTEX (PFC) OF RATS EXPOSED TO STRESS AND TREATMENT. STRESS INCREASED DNA METHYLATION, DNMT3A AND DNMT3B EXPRESSION IN THE DHPC AND PFC. CHRONIC, BUT NOT ACUTE, IMIPRAMINE ADMINISTRATION ATTENUATED STRESS EFFECTS ONLY IN THE PFC. THESE RESULTS SUGGEST THE REGULATION OF DNA METHYLATION IN THE PFC MAY BE AN IMPORTANT MECHANISM FOR ANTIDEPRESSANT-LIKE EFFECTS IN THE LH MODEL. 2018 15 1626 25 DNMT1 MEDIATES CHRONIC PAIN-RELATED DEPRESSION BY INHIBITING GABAERGIC NEURONAL ACTIVATION IN THE CENTRAL AMYGDALA. BACKGROUND: CHRONIC PAIN CAN INDUCE DEPRESSIVE EMOTION. DNA METHYLTRANSFERASES (DNMTS) HAVE BEEN SHOWN TO BE INVOLVED IN THE DEVELOPMENT OF CHRONIC PAIN AND DEPRESSION. HOWEVER, THE ROLE AND MECHANISM OF DNMTS IN CHRONIC PAIN-INDUCED DEPRESSION ARE NOT WELL UNDERSTOOD. METHODS: IN WELL-ESTABLISHED SPARED NERVE INJURY (SNI)-INDUCED CHRONIC PAIN-RELATED DEPRESSION MODELS, THE EXPRESSION OF DNMTS AND THE FUNCTIONAL ROLES AND UNDERLYING MECHANISMS OF DNMT1 IN CENTRAL AMYGDALA (CEA) GABAERGIC (GAMMA-AMINOBUTYRIC ACIDERGIC) NEURONS WERE INVESTIGATED USING MOLECULAR, PHARMACOLOGICAL, ELECTROPHYSIOLOGICAL, OPTOGENETIC, AND CHEMOGENETIC TECHNIQUES AND BEHAVIORAL TESTS. RESULTS: DNMT1, BUT NOT DNMT3A OR DNMT3B, WAS UPREGULATED IN THE CEA OF RATS WITH SNI-INDUCED CHRONIC PAIN-DEPRESSION. INHIBITION OF DNMT1 BY 5-AZA OR VIRAL KNOCKDOWN OF DNMT1 IN GABAERGIC NEURONS IN THE CEA EFFECTIVELY AMELIORATED THE DEPRESSION-LIKE BEHAVIORS INDUCED BY CHRONIC PAIN. THE DNMT1 ACTION WAS ASSOCIATED WITH METHYLATION AT THE CPG-RICH GAD1 PROMOTER AND GAD67 DOWNREGULATION, LEADING TO A DECREASE OF GABAERGIC NEURONAL ACTIVITY. OPTOGENETIC ACTIVATION OF GABAERGIC NEURONS IN THE CEA IMPROVED SNI-INDUCED DEPRESSION-LIKE BEHAVIORS. MOREOVER, OPTOGENETIC OR CHEMOGENETIC INHIBITION OF GABAERGIC NEURONS IN THE CEA REVERSED DNMT1 KNOCKDOWN-INDUCED IMPROVEMENT OF DEPRESSION-LIKE BEHAVIORS IN SNI MICE. CONCLUSIONS: OUR FINDINGS SUGGEST THAT DNMT1 IS INVOLVED IN THE DEVELOPMENT OF CHRONIC PAIN-RELATED DEPRESSION BY EPIGENETIC REPRESSION OF GAD67, LEADING TO THE INHIBITION OF GABAERGIC NEURONAL ACTIVATION. THIS STUDY INDICATES THAT DNMT1 COULD BE A POTENTIAL TARGET FOR THE TREATMENT OF CHRONIC PAIN-RELATED DEPRESSION. 2023 16 1831 28 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 17 2272 19 EPIGENETIC REDUCTION OF MIR-214-3P UPREGULATES ASTROCYTIC COLONY-STIMULATING FACTOR-1 AND CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY NERVE INJURY. EMERGING EVIDENCE HAS INDICATED THAT COLONY-STIMULATING FACTOR-1 (CSF1) MODULATES NEUROINFLAMMATION IN THE CENTRAL NERVOUS SYSTEM AND THE DEVELOPMENT OF NEUROPATHIC PAIN, WHILE THE UNDERLYING MECHANISM REMAINS UNKNOWN. HERE, WE IDENTIFIED THE INCREASED EXPRESSION OF CSF1 DERIVED FROM ACTIVATED ASTROCYTES IN THE IPSILATERAL DORSAL HORN IN RATS WITH SPINAL NERVE LIGATION (SNL). SUPPRESSION OF CSF1 EXPRESSION ALLEVIATED NEUROINFLAMMATION, NEURONAL HYPEREXCITABILITY, AND GLUTAMATERGIC RECEPTOR SUBUNIT UPREGULATION IN THE DORSAL HORN AND IMPROVED SNL-INDUCED PAIN BEHAVIOR. WE ALSO FOUND REDUCED MIR-214-3P EXPRESSION IN THE IPSILATERAL DORSAL HORN FOLLOWING AN SNL PROCEDURE; MIR-214-3P DIRECTLY BOUND TO THE 3'-UTR OF CSF1 MRNA AND NEGATIVELY REGULATED CSF1 EXPRESSION. INTRATHECAL DELIVERY OF MIR-214-3P MIMIC REVERSED THE ENHANCED EXPRESSION OF CSF1 AND ASTROCYTE OVERACTIVITY AND ALLEVIATED THE IL-6 UPREGULATION AND PAIN BEHAVIOR INDUCED BY SNL. MOREOVER, SUPPRESSION OF SPINAL MIR-214-3P INCREASED ASTROCYTE REACTIVITY, PROMOTED CSF1 AND IL-6 PRODUCTION, AND INDUCED PAIN HYPERSENSITIVITY IN NAIVE ANIMALS. FURTHERMORE, SNL INDUCED THE EXPRESSION OF DNA METHYLTRANSFERASE 3A (DNMT3A) THAT WAS ASSOCIATED WITH THE HYPERMETHYLATION OF THE MIR-214-3P PROMOTER, LEADING TO REDUCED MIR-214-3P EXPRESSION IN THE MODEL RODENTS. TREATMENT WITH THE DNMT INHIBITOR ZEBULARINE SIGNIFICANTLY REDUCED CYTOSINE METHYLATION IN THE MIR-214-3P PROMOTER; THIS REDUCED METHYLATION CONSEQUENTLY INCREASED THE EXPRESSION OF MIR-214-3P AND DECREASED THE CONTENT OF CSF1 IN THE IPSILATERAL DORSAL HORN AND, FURTHER, ATTENUATED IL-6 PRODUCTION AND PAIN BEHAVIOR IN RATS WITH SNL. TOGETHER, OUR DATA INDICATE THAT THE DNMT3A-MEDIATED EPIGENETIC SUPPRESSION OF MIR-214-3P ENHANCED CSF1 PRODUCTION IN ASTROCYTES, WHICH SUBSEQUENTLY INDUCED NEUROINFLAMMATION AND PAIN BEHAVIOR IN SNL MODEL RATS. 2020 18 4397 28 MODULATION OF DNA METHYLATION AND GENE EXPRESSION IN RODENT CORTICAL NEUROPLASTICITY PATHWAYS EXERTS RAPID ANTIDEPRESSANT-LIKE EFFECTS. BACKGROUND: STRESS INCREASES DNA METHYLATION, PRIMARILY A SUPPRESSIVE EPIGENETIC MECHANISM CATALYZED BY DNA METHYLTRANSFERASES (DNMT), AND DECREASES THE EXPRESSION OF GENES INVOLVED IN NEURONAL PLASTICITY AND MOOD REGULATION. DESPITE CHRONIC ANTIDEPRESSANT TREATMENT DECREASES STRESS-INDUCED DNA METHYLATION, IT IS NOT KNOWN WHETHER INHIBITION OF DNMT WOULD CONVEY RAPID ANTIDEPRESSANT-LIKE EFFECTS. AIM: THIS WORK TESTED SUCH A HYPOTHESIS AND EVALUATED WHETHER A BEHAVIORAL EFFECT INDUCED BY DNMT INHIBITORS (DNMTI) CORRESPONDS WITH CHANGES IN DNA METHYLATION AND TRANSCRIPT LEVELS IN GENES CONSISTENTLY ASSOCIATED WITH THE NEUROBIOLOGY OF DEPRESSION AND SYNAPTIC PLASTICITY (BDNF, TRKB, 5-HT(1A), NMDA, AND AMPA). METHODS: MALE WISTAR RATS RECEIVED INTRAPERITONEAL (I.P.) INJECTION OF TWO PHARMACOLOGICALLY DIFFERENT DNMTI (5-AZAD 0.2 AND 0.6 MG/KG OR RG108 0.6 MG/KG) OR VEHICLE (1 ML/KG), 1 H OR 7 DAYS BEFORE THE LEARNED HELPLESSNESS TEST (LH). DNA METHYLATION IN TARGET GENES AND THE CORRESPONDENT TRANSCRIPT LEVELS WERE MEASURED IN THE HIPPOCAMPUS (HPC) AND PREFRONTAL CORTEX (PFC) USING MEDIP-QPCR. IN PARALLEL SEPARATE GROUPS, THE ANTIDEPRESSANT-LIKE EFFECT OF 5-AZAD AND RG108 WAS INVESTIGATED IN THE FORCED SWIMMING TEST (FST). THE INVOLVEMENT OF CORTICAL BDNF-TRKB-MTOR PATHWAYS WAS ASSESSED BY INTRA-VENTRAL MEDIAL PFC (VMPFC) INJECTIONS OF RAPAMYCIN (MTOR INHIBITOR), K252A (TRKB RECEPTOR ANTAGONIST), OR VEHICLE (0.2 MUL/SIDE). RESULTS: WE FOUND THAT BOTH 5-AZAD AND RG108 ACUTELY AND 7 DAYS BEFORE THE TEST DECREASED ESCAPE FAILURES IN THE LH. LH STRESS INCREASED DNA METHYLATION AND DECREASED TRANSCRIPT LEVELS OF BDNF IV AND TRKB IN THE PFC, EFFECTS THAT WERE NOT SIGNIFICANTLY ATTENUATED BY RG108 TREATMENT. THE SYSTEMIC ADMINISTRATION OF 5-AZAD (0.2 MG/KG) AND RG108 (0.2 MG/KG) INDUCED AN ANTIDEPRESSANT-LIKE EFFECT IN FST, WHICH WAS, HOWEVER, ATTENUATED BY TRKB AND MTOR INHIBITION INTO THE VMPFC. CONCLUSION: THESE FINDINGS SUGGEST THAT ACUTE INHIBITION OF STRESS-INDUCED DNA METHYLATION PROMOTES RAPID AND SUSTAINED ANTIDEPRESSANT EFFECTS ASSOCIATED WITH INCREASED BDNF-TRKB-MTOR SIGNALING IN THE PFC. 2021 19 1698 26 DYNAMIC EFFECTS OF EARLY ADOLESCENT STRESS ON DEPRESSIVE-LIKE BEHAVIORS AND EXPRESSION OF CYTOKINES AND JMJD3 IN THE PREFRONTAL CORTEX AND HIPPOCAMPUS OF RATS. AIMS: EXPRESSION OF INFLAMMATORY CYTOKINES IN THE BRAIN HAS BEEN REPORTED TO BE INVOLVED IN THE PATHOGENESIS OF AND SUSCEPTIBILITY TO DEPRESSION. JUMONJI DOMAIN-CONTAINING 3 (JMJD3), WHICH IS A HISTONE H3 LYSINE 27 (H3K27) DEMETHYLASE AND CAN REGULATE MICROGLIAL ACTIVATION, HAS BEEN REGARDED AS A CRUCIAL ELEMENT IN THE EXPRESSION OF INFLAMMATORY CYTOKINES. FURTHERMORE, RECENT STUDIES HIGHLIGHTED THE FACT THAT LIPOPOLYSACCHARIDES INDUCE DEPRESSIVE-LIKE BEHAVIORS AND HIGHER JMJD3 EXPRESSION AND LOWER H3K27ME3 EXPRESSION IN THE BRAIN. HOWEVER, WHETHER THE PROCESS OF JMJD3 MEDIATING INFLAMMATORY CYTOKINES WAS INVOLVED IN THE SUSCEPTIBILITY TO DEPRESSION DUE TO EARLY-LIFE STRESS REMAINED ELUSIVE. METHODS: RATS EXPOSED TO CHRONIC UNPREDICTABLE MILD STRESS (CUMS) IN ADOLESCENCE WERE USED IN ORDER TO DETECT DYNAMIC ALTERATIONS IN DEPRESSIVE-LIKE BEHAVIORS AND EXPRESSION OF CYTOKINES, JMJD3, AND H3K27ME3 IN THE PREFRONTAL CORTEX AND HIPPOCAMPUS. MOREOVER, MINOCYCLINE, AN INHIBITOR OF MICROGLIAL ACTIVATION, WAS EMPLOYED TO OBSERVE THE PROTECTIVE EFFECTS. RESULTS: OUR RESULTS SHOWED THAT CUMS DURING THE ADOLESCENT PERIOD INDUCED DEPRESSIVE-LIKE BEHAVIORS, OVER-EXPRESSION OF CYTOKINES, AND INCREASED JMJD3 AND DECREASED H3K27ME3 EXPRESSION IN THE PREFRONTAL CORTEX AND HIPPOCAMPUS OF BOTH ADOLESCENT AND ADULT RATS. HOWEVER, MINOCYCLINE RELIEVED ALL THE ALTERATIONS. CONCLUSION: THE STUDY REVEALED THAT JMJD3 MIGHT BE INVOLVED IN THE SUSCEPTIBILITY TO DEPRESSIVE-LIKE BEHAVIORS BY MODULATING H3K27ME3 AND PRO-INFLAMMATORY CYTOKINE EXPRESSION IN THE PREFRONTAL CORTEX AND HIPPOCAMPUS OF RATS THAT HAD BEEN STRESSED DURING EARLY ADOLESCENCE. 2018 20 1653 35 DOPAMINE TRANSPORTER KNOCKOUT RATS DISPLAY EPIGENETIC ALTERATIONS IN RESPONSE TO COCAINE EXPOSURE. (1) BACKGROUND: THERE IS AN URGENT NEED FOR EFFECTIVE TREATMENTS FOR COCAINE USE DISORDER (CUD), AND NEW PHARMACOLOGICAL APPROACHES TARGETING EPIGENETIC MECHANISMS APPEAR TO BE PROMISING OPTIONS FOR THE TREATMENT OF THIS DISEASE. DOPAMINE TRANSPORTER (DAT) TRANSGENIC RATS RECENTLY HAVE BEEN PROPOSED AS A NEW ANIMAL MODEL FOR STUDYING SUSCEPTIBILITY TO CUD. (2) METHODS: DAT TRANSGENIC RATS WERE TREATED CHRONICALLY WITH COCAINE (10 MG/KG) FOR 8 DAYS, AND THE EXPRESSION OF EPIGENETIC MODULATORS, LYSINE DEMETHYLASE 6B (KDM6B) AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4), WAS EXAMINED IN THE PREFRONTAL CORTEX (PFC). (3) RESULTS: WE SHOW THAT ONLY FULL KNOCKOUT (KO) OF DAT IMPACTS BASAL LEVELS OF KDM6B IN FEMALES. ADDITIONALLY, COCAINE ALTERED THE EXPRESSION OF BOTH EPIGENETIC MARKERS IN A SEX- AND GENOTYPE-DEPENDENT MANNER. IN RESPONSE TO CHRONIC COCAINE, KDM6B EXPRESSION WAS DECREASED IN MALE RATS WITH PARTIAL DAT MUTATION (HET), WHILE NO CHANGES WERE OBSERVED IN WILD-TYPE (WT) OR KO RATS. INDEED, WHILE HET MALE RATS HAVE REDUCED KDM6B AND BRD4 EXPRESSION, HET FEMALE RATS SHOWED INCREASED KDM6B AND BRD4 EXPRESSION LEVELS, HIGHLIGHTING THE IMPACT OF SEX ON EPIGENETIC MECHANISMS IN RESPONSE TO COCAINE. FINALLY, BOTH MALE AND FEMALE KO RATS SHOWED INCREASED EXPRESSION OF BRD4, BUT ONLY KO FEMALES EXHIBITED SIGNIFICANTLY INCREASED KDM6B EXPRESSION IN RESPONSE TO COCAINE. ADDITIONALLY, THE MAGNITUDE OF THESE EFFECTS WAS BIGGER IN FEMALES WHEN COMPARED TO MALES FOR BOTH EPIGENETIC ENZYMES. (4) CONCLUSIONS: THIS PRELIMINARY STUDY PROVIDES ADDITIONAL SUPPORT THAT TARGETING KDM6B AND/OR BRD4 MAY POTENTIALLY BE THERAPEUTIC IN TREATING ADDICTION-RELATED BEHAVIORS IN A SEX-DEPENDENT MANNER. 2023