1  2480 105 EPIGENETIC UPREGULATION OF LARGE-CONDUCTANCE CA2+-ACTIVATED K+ CHANNEL EXPRESSION IN UTERINE VASCULAR ADAPTATION TO PREGNANCY. OUR PREVIOUS STUDY DEMONSTRATED THAT PREGNANCY INCREASED LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL BETA1 SUBUNIT (BKBETA1) EXPRESSION AND LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL ACTIVITY IN UTERINE ARTERIES, WHICH WERE ABROGATED BY CHRONIC HYPOXIA. THE PRESENT STUDY TESTED THE HYPOTHESIS THAT PROMOTER METHYLATION/DEMETHYLATION IS A KEY MECHANISM IN EPIGENETIC REPROGRAMMING OF BKBETA1 EXPRESSION PATTERNS IN UTERINE ARTERIES. OVINE BKBETA1 PROMOTER OF 2315 BP SPANNING FROM -2211 TO +104 OF THE TRANSCRIPTION START SITE WAS CLONED, AND AN SP1-380 BINDING SITE THAT CONTAINS CPG DINUCLEOTIDE IN ITS CORE BINDING SEQUENCES WAS IDENTIFIED. SITE-DIRECTED DELETION OF THE SP1 SITE SIGNIFICANTLY DECREASED THE BKBETA1 PROMOTER ACTIVITY. ESTROGEN RECEPTOR-ALPHA BOUND TO THE SP1 SITE THROUGH TETHERING TO SP1 AND UPREGULATED THE EXPRESSION OF BKBETA1. THE SP1 BINDING SITE AT BKBETA1 PROMOTER WAS HIGHLY METHYLATED IN UTERINE ARTERIES OF NONPREGNANT SHEEP, AND METHYLATION INHIBITED TRANSCRIPTION FACTOR BINDING AND BKBETA1 PROMOTER ACTIVITY. PREGNANCY CAUSED A SIGNIFICANT DECREASE IN CPG METHYLATION AT THE SP1 BINDING SITE AND INCREASED SP1 BINDING TO THE BKBETA1 PROMOTER AND BKBETA1 MRNA ABUNDANCE. CHRONIC HYPOXIA DURING GESTATION ABROGATED THIS PREGNANCY-INDUCED DEMETHYLATION AND UPREGULATION OF BKBETA1 EXPRESSION. THE RESULTS PROVIDE EVIDENCE OF A NOVEL MECHANISM OF PROMOTER DEMETHYLATION IN PREGNANCY-INDUCED REPROGRAMMING OF LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL EXPRESSION AND FUNCTION IN UTERINE ARTERIES AND SUGGEST NEW INSIGHTS OF EPIGENETIC MECHANISMS LINKING GESTATIONAL HYPOXIA TO ABERRANT UTEROPLACENTAL CIRCULATION AND INCREASED RISK OF PREECLAMPSIA.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
2   919  70 CHRONIC HYPOXIA DURING GESTATION CAUSES EPIGENETIC REPRESSION OF THE ESTROGEN RECEPTOR-ALPHA GENE IN OVINE UTERINE ARTERIES VIA HEIGHTENED PROMOTER METHYLATION. ESTROGEN RECEPTOR-ALPHA (ERALPHA) PLAYS A KEY ROLE IN THE ADAPTATION OF INCREASED UTERINE BLOOD FLOW IN PREGNANCY. CHRONIC HYPOXIA IS A COMMON STRESS TO MATERNAL CARDIOVASCULAR HOMEOSTASIS AND CAUSES INCREASED RISK OF PREECLAMPSIA. STUDIES IN PREGNANT SHEEP DEMONSTRATED THAT HYPOXIA DURING GESTATION DOWNREGULATED ERALPHA GENE EXPRESSION IN UTERINE ARTERIES. THE PRESENT STUDY TESTED THE HYPOTHESIS THAT HYPOXIA CAUSES EPIGENETIC REPRESSION OF THE ERALPHA GENE IN UTERINE ARTERIES VIA HEIGHTENED PROMOTER METHYLATION. OVINE ERALPHA PROMOTER OF 2035 BP SPANNING FROM -2000 TO +35 OF THE TRANSCRIPTION START SITE WAS CLONED. NO ESTROGEN OR HYPOXIA-INDUCIBLE FACTOR RESPONSE ELEMENTS WERE FOUND AT THE PROMOTER. TWO TRANSCRIPTION FACTOR BINDING SITES, USF(-15) AND SP1(-520), CONTAINING CPG DINUCLEOTIDES WERE IDENTIFIED, WHICH HAD SIGNIFICANT EFFECTS ON THE PROMOTER ACTIVITY. THE USF ELEMENT BINDS TRANSCRIPTION FACTORS USF1 AND USF2, AND THE SP1 ELEMENT BINDS SP1, AS WELL AS ERALPHA THROUGH SP1. DELETION OF THE SP1 SITE ABROGATED 17BETA-ESTRADIOL-INDUCED INCREASE IN THE PROMOTER ACTIVITY. IN NORMOXIC CONTROL SHEEP, CPG METHYLATION AT THE SP1 BUT NOT THE USF SITE WAS SIGNIFICANTLY DECREASED IN UTERINE ARTERIES OF PREGNANT AS COMPARED WITH NONPREGNANT ANIMALS. IN PREGNANT SHEEP EXPOSED TO LONG-TERM HIGH-ALTITUDE HYPOXIA, CPG METHYLATION AT BOTH SP1 AND USF SITES IN UTERINE ARTERIES WAS SIGNIFICANTLY INCREASED. METHYLATION INHIBITED TRANSCRIPTION FACTOR BINDING AND THE PROMOTER ACTIVITY. THE RESULTS PROVIDE EVIDENCE OF HYPOXIA CAUSING HEIGHTENED PROMOTER METHYLATION AND RESULTANT ERALPHA GENE REPRESSION IN UTERINE ARTERIES AND SUGGEST NEW INSIGHTS OF MOLECULAR MECHANISMS LINKING GESTATIONAL HYPOXIA TO ABERRANT UTEROPLACENTAL CIRCULATION AND INCREASED RISK OF PREECLAMPSIA.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
3   840  26 CHEMOENZYMATIC LABELING OF DNA METHYLATION PATTERNS FOR SINGLE-MOLECULE EPIGENETIC MAPPING. DNA METHYLATION, SPECIFICALLY, METHYLATION OF CYTOSINE (C) NUCLEOTIDES AT THE 5-CARBON POSITION (5-MC), IS THE MOST STUDIED AND SIGNIFICANT EPIGENETIC MODIFICATION. HERE WE DEVELOPED A CHEMOENZYMATIC PROCEDURE TO FLUORESCENTLY LABEL NON-METHYLATED CYTOSINES IN CPG CONTEXT, ALLOWING EPIGENETIC PROFILING OF SINGLE DNA MOLECULES SPANNING HUNDREDS OF THOUSANDS OF BASE PAIRS. WE USED A CPG METHYLTRANSFERASE WITH A SYNTHETIC S-ADENOSYL-L-METHIONINE COFACTOR ANALOG TO TRANSFER AN AZIDE TO CYTOSINES INSTEAD OF THE NATURAL METHYL GROUP. A FLUOROPHORE WAS THEN CLICKED ONTO THE DNA, REPORTING ON THE AMOUNT AND POSITION OF NON-METHYLATED CPGS. WE FOUND THAT LABELING EFFICIENCY WAS INCREASED UP TO 2-FOLD BY THE ADDITION OF A NUCLEOSIDASE, PRESUMABLY BY DEGRADING THE INACTIVE BY-PRODUCT OF THE COFACTOR AFTER LABELING, PREVENTING ITS INHIBITORY EFFECT. WE USED THE METHOD TO DETERMINE THE DECLINE IN GLOBAL DNA METHYLATION IN A CHRONIC LYMPHOCYTIC LEUKEMIA PATIENT AND THEN PERFORMED WHOLE-GENOME METHYLATION MAPPING OF THE MODEL PLANT ARABIDOPSIS THALIANA. OUR GENOME MAPS SHOW HIGH CONCORDANCE WITH PUBLISHED BISULFITE SEQUENCING METHYLATION MAPS. ALTHOUGH MAPPING RESOLUTION IS LIMITED BY OPTICAL DETECTION TO 500-1000 BP, THE LABELED DNA MOLECULES PRODUCED BY THIS APPROACH ARE HUNDREDS OF THOUSANDS OF BASE PAIRS LONG, ALLOWING ACCESS TO LONG REPETITIVE AND STRUCTURALLY VARIABLE GENOMIC REGIONS.	2022	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
4   519  28 ASSOCIATIONS BETWEEN GENETIC AND EPIGENETIC VARIATIONS IN CYTOKINE GENES AND MILD PERSISTENT BREAST PAIN IN WOMEN FOLLOWING BREAST CANCER SURGERY. PERSISTENT PAIN FOLLOWING BREAST CANCER SURGERY IS A SIGNIFICANT PROBLEM. BOTH INHERITED AND ACQUIRED MECHANISMS OF INFLAMMATION APPEAR TO PLAY A ROLE IN THE DEVELOPMENT AND MAINTENANCE OF PERSISTENT PAIN. IN THIS LONGITUDINAL STUDY, GROWTH MIXTURE MODELING WAS USED TO IDENTIFY PERSISTENT BREAST PAIN PHENOTYPES BASED ON PAIN ASSESSMENTS OBTAINED PRIOR TO AND MONTHLY FOR 6MONTHS FOLLOWING BREAST CANCER SURGERY. ASSOCIATIONS BETWEEN THE "NO PAIN" AND "MILD PAIN" PHENOTYPES AND SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) SPANNING 15 CYTOKINE GENES WERE EVALUATED. THE METHYLATION STATUS OF THE CPG SITES FOUND IN THE PROMOTERS OF GENES ASSOCIATED WITH PAIN GROUP MEMBERSHIP WAS DETERMINED USING BISULFITE SEQUENCING. IN THE MULTIVARIATE ANALYSIS, THREE SNPS (I.E., INTERLEUKIN 6 (IL6) RS2069840, C-X-C MOTIF CHEMOKINE LIGAND 8 (CXCL8) RS4073, TUMOR NECROSIS FACTOR (TNF) RS1800610) AND TWO TNF CPG SITES (I.E., C.-350C, C.-344C) WERE ASSOCIATED WITH PAIN GROUP MEMBERSHIP. THESE FINDINGS SUGGEST THAT VARIATIONS IN IL6, CXCL8, AND TNF ARE ASSOCIATED WITH THE DEVELOPMENT AND MAINTENANCE OF MILD PERSISTENT BREAST PAIN. CPG METHYLATION WITHIN THE TNF PROMOTER MAY PROVIDE AN ADDITIONAL MECHANISM THROUGH WHICH TNF ALTERS THE RISK FOR MILD PERSISTENT BREAST PAIN AFTER BREAST CANCER SURGERY. THESE GENETIC AND EPIGENETIC VARIATIONS MAY HELP TO IDENTIFY INDIVIDUALS WHO ARE PREDISPOSED TO THE DEVELOPMENT OF MILD LEVELS OF PERSISTENT BREAST PAIN FOLLOWING BREAST CANCER SURGERY.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
5  2756  24 EXPRESSION OF DNA METHYLTRANSFERASES IN ADULT DORSAL ROOT GANGLIA IS CELL-TYPE SPECIFIC AND UP REGULATED IN A RODENT MODEL OF NEUROPATHIC PAIN. NEUROPATHIC PAIN IS ASSOCIATED WITH HYPEREXCITABILITY AND INTRINSIC FIRING OF DORSAL ROOT GANGLIA (DRG) NEURONS. THESE PHENOTYPICAL CHANGES CAN BE LONG LASTING, POTENTIALLY SPANNING THE ENTIRE LIFE OF ANIMAL MODELS, AND DEPEND ON ALTERED EXPRESSION OF NUMEROUS PROTEINS, INCLUDING MANY ION CHANNELS. YET, HOW DRGS MAINTAIN LONG-TERM CHANGES IN PROTEIN EXPRESSION IN NEUROPATHIC CONDITIONS REMAINS UNCLEAR. DNA METHYLATION IS A WELL-KNOWN MECHANISM OF EPIGENETIC CONTROL OF GENE EXPRESSION AND IS ACHIEVED BY THE ACTION OF THREE ENZYMES: DNA METHYLTRANSFERASE (DNMT) 1, 3A, AND 3B, WHICH HAVE BEEN STUDIED PRIMARILY DURING DEVELOPMENT. WE FIRST PERFORMED IMMUNOHISTOCHEMICAL ANALYSIS TO ASSESS WHETHER THESE ENZYMES ARE EXPRESSED IN ADULT RAT DRGS (L4-5) AND FOUND THAT DNMT1 IS EXPRESSED IN BOTH GLIA AND NEURONS, DNMT3A IS PREFERENTIALLY EXPRESSED IN GLIA AND DNMT3B IS PREFERENTIALLY EXPRESSED IN NEURONS. A RAT MODEL OF NEUROPATHIC PAIN WAS THEN USED TO DETERMINE WHETHER NERVE INJURY MAY INDUCE EPIGENETIC CHANGES IN DRGS AT MULTIPLE TIME POINTS AFTER PAIN ONSET. REAL-TIME RT PCR ANALYSIS REVEALED ROBUST AND TIME-DEPENDENT CHANGES IN DNMT TRANSCRIPT EXPRESSION IN IPSILATERAL DRGS FROM SPARED NERVE INJURY (SNI) BUT NOT SHAM RATS. INTERESTINGLY, DNMT3B TRANSCRIPT SHOWED A ROBUST UPREGULATION THAT APPEARED ALREADY 1 WEEK AFTER SURGERY AND PERSISTED AT 4 WEEKS (OUR ENDPOINT); IN CONTRAST, DNMT1 AND DNMT3A TRANSCRIPTS SHOWED ONLY MODERATE UPREGULATION THAT WAS TRANSIENT AND DID NOT APPEAR UNTIL THE SECOND WEEK. WE SUGGEST THAT DNMT REGULATION IN ADULT DRGS MAY BE A CONTRIBUTOR TO THE PAIN PHENOTYPE AND MERITS FURTHER STUDY.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
6  4408  31 MOLECULAR ANALYSIS OF THE FRAGILE HISTIDINE TRIAD (FHIT) TUMOR SUPPRESSOR GENE IN VESICAL TUMORS OF CATTLE WITH CHRONIC ENZOOTIC HEMATURIA (CEH). THE FHIT (FRAGILE HISTIDINE TRIAD) GENE IS A TUMOR SUPPRESSOR GENE KNOWN TO BE INACTIVATED IN MANY TUMORS INCLUDING BLADDER TUMORS AND IS SPANNING FRA3B, A VERY ACTIVE COMMON FRAGILE SITE IN THE HUMAN GENOME. WE HAVE RECENTLY ISOLATED THE BOVINE GENE, AND THE AIM OF THIS STUDY WAS TO TEST WHETHER FHIT PRESENTS ALTERED EXPRESSION PATTERNS IN VESICAL TUMORS OF CATTLE WITH CEH (CHRONIC ENZOOTIC HEMATURIA). CEH IS A COMMON SYNDROME AFFECTING MEDITERRANEAN CATTLE: CLASTOGENIC, MUTAGENIC AND CANCEROGENIC SUBSTANCES RELEASED BY THE BRACKEN FERN (PTERIDIUM SPP) GRAZED BY ANIMALS INDUCE THE FORMATION OF NEOPLASTIC LESIONS, AMONG WHICH BLADDER TUMORS HAVE A HIGH INCIDENCE. WE ANALYSED FHIT IN 23 BLADDER TUMORS OF CEH CATTLE LOOKING AT: 1) THE METHYLATION STATUS OF THE CPG ISLAND COMPRISING THE PROMOTER AND PART OF EXON 1; 2) THE PRESENCE OF ALTERED FHIT TRANSCRIPTS; 3) THE MRNA EXPRESSION LEVELS MEASURED WITH A QUANTITATIVE REAL TIME PCR (QRT-PCR) APPROACH. OUR RESULTS SUGGEST THAT UNLIKE IN HUMAN TUMORS, FHIT IN VESICAL TUMORS OF CEH CATTLE IS LARGELY UNMETHYLATED. FURTHERMORE, THE SAME MRNA ISOFORMS OF FHIT WERE DETECTED IN TUMORS AND IN HEALTHY TISSUES, INCLUDING A NOVEL ISOFORM THAT WAS FOUND IN THIS STUDY. FINALLY, QRT-PCR DATA DID NOT REVEAL SIGNIFICANTLY ALTERED EXPRESSION PROFILES OF FHIT TRANSCRIPTS. FURTHER STUDIES AND LARGER SETS OF CASES WILL BE USEFUL TO CONFIRM THIS FINDING, BUT THE DATA SEEM TO SUGGEST THAT EPIGENETIC MODIFICATIONS OF FHIT AND ALTERED EXPRESSION PROFILES ARE NOT A HALLMARK OF BOVINE VESICAL TUMORS LIKE THEY ARE IN HUMAN TUMORS.	2008	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
7  3051  22 GENOME-WIDE ASSOCIATION ANALYSIS OF EOSINOPHILIC ESOPHAGITIS PROVIDES INSIGHT INTO THE TISSUE SPECIFICITY OF THIS ALLERGIC DISEASE. EOSINOPHILIC ESOPHAGITIS (EOE) IS A CHRONIC INFLAMMATORY DISORDER ASSOCIATED WITH ALLERGIC HYPERSENSITIVITY TO FOOD. WE INTERROGATED >1.5 MILLION GENETIC VARIANTS IN EOE CASES OF EUROPEAN ANCESTRY AND SUBSEQUENTLY IN A MULTI-SITE COHORT WITH LOCAL AND OUT-OF-STUDY CONTROL SUBJECTS. IN ADDITION TO REPLICATING ASSOCIATION OF THE 5Q22 LOCUS (META-ANALYSIS P=1.9X10(-16)), WE IDENTIFIED AN ASSOCIATION AT 2P23 SPANNING CAPN14 (P=2.5X10(-10)). CAPN14 WAS SPECIFICALLY EXPRESSED IN THE ESOPHAGUS, WAS DYNAMICALLY UPREGULATED AS A FUNCTION OF DISEASE ACTIVITY AND GENETIC HAPLOTYPE AND AFTER EXPOSURE OF EPITHELIAL CELLS TO INTERLEUKIN (IL)-13, AND WAS LOCATED IN AN EPIGENETIC HOTSPOT MODIFIED BY IL-13. GENES NEIGHBORING THE TOP 208 EOE-ASSOCIATED SEQUENCE VARIANTS WERE ENRICHED FOR ESOPHAGEAL EXPRESSION, AND MULTIPLE LOCI FOR ALLERGIC SENSITIZATION WERE ASSOCIATED WITH EOE SUSCEPTIBILITY (4.8X10(-2)<P<5.1X10(-11)). WE PROPOSE A MODEL TO EXPLAIN THE TISSUE-SPECIFIC NATURE OF EOE THAT INVOLVES THE INTERPLAY OF ALLERGIC SENSITIZATION WITH AN EOE-SPECIFIC, IL-13-INDUCIBLE ESOPHAGEAL RESPONSE INVOLVING CAPN14.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
8   800  17 CELLULAR, MOLECULAR, AND EPIGENETIC MECHANISMS IN NON-ASSOCIATIVE CONDITIONING: IMPLICATIONS FOR PAIN AND MEMORY. SENSITIZATION IS A FORM OF NON-ASSOCIATIVE CONDITIONING IN WHICH AMPLIFICATION OF BEHAVIORAL RESPONSES CAN OCCUR FOLLOWING PRESENTATION OF AN AVERSIVE OR NOXIOUS STIMULUS. UNDERSTANDING THE CELLULAR AND MOLECULAR UNDERPINNINGS OF SENSITIZATION HAS BEEN AN OVERARCHING THEME SPANNING THE FIELD OF LEARNING AND MEMORY AS WELL AS THAT OF PAIN RESEARCH. IN THIS REVIEW WE EXAMINE HOW SENSITIZATION, BOTH IN THE CONTEXT OF LEARNING AS WELL AS PAIN PROCESSING, SHARES EVOLUTIONARILY CONSERVED BEHAVIORAL, CELLULAR/SYNAPTIC, AND EPIGENETIC MECHANISMS ACROSS PHYLA. FIRST, WE CHARACTERIZE THE BEHAVIORAL PHENOMENON OF SENSITIZATION BOTH IN INVERTEBRATES AND VERTEBRATES. PARTICULAR EMPHASIS IS PLACED ON LONG-TERM SENSITIZATION (LTS) OF WITHDRAWAL REFLEXES IN APLYSIA FOLLOWING AVERSIVE STIMULATION OR INJURY, ALTHOUGH ADDITIONAL INVERTEBRATE MODELS ARE ALSO COVERED. IN THE CONTEXT OF VERTEBRATES, SENSITIZATION OF MAMMALIAN HYPERAROUSAL IN A MODEL OF POST-TRAUMATIC STRESS DISORDER (PTSD), AS WELL AS MAMMALIAN MODELS OF INFLAMMATORY AND NEUROPATHIC PAIN IS CHARACTERIZED. SECOND, WE INVESTIGATE THE CELLULAR AND SYNAPTIC MECHANISMS UNDERLYING THESE BEHAVIORS. WE FOCUS OUR DISCUSSION ON SEROTONIN-MEDIATED LONG-TERM FACILITATION (LTF) AND AXOTOMY-MEDIATED LONG-TERM HYPEREXCITABILITY (LTH) IN REDUCED APLYSIA SYSTEMS, AS WELL AS MAMMALIAN SPINAL PLASTICITY MECHANISMS OF CENTRAL SENSITIZATION. THIRD, WE EXPLORE RECENT EVIDENCE IMPLICATING EPIGENETIC MECHANISMS IN LEARNING- AND PAIN-RELATED SENSITIZATION. THIS REVIEW ILLUSTRATES THE FUNDAMENTAL AND FUNCTIONAL OVERLAY OF THE LEARNING AND MEMORY FIELD WITH THE PAIN FIELD WHICH ARGUES FOR HOMOLOGOUS PERSISTENT PLASTICITY MECHANISMS IN RESPONSE TO SENSITIZING STIMULI OR INJURY ACROSS PHYLA.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
9  4650  23 NEUROPLASTICITY IN ADDICTION: CELLULAR AND TRANSCRIPTIONAL PERSPECTIVES. DRUG ADDICTION IS A CHRONIC, RELAPSING BRAIN DISORDER WHICH CONSISTS OF COMPULSIVE PATTERNS OF DRUG-SEEKING AND TAKING THAT OCCURS AT THE EXPENSE OF OTHER ACTIVITIES. THE TRANSITION FROM CASUAL TO COMPULSIVE DRUG USE AND THE ENDURING PROPENSITY TO RELAPSE IS THOUGHT TO BE UNDERPINNED BY LONG-LASTING NEUROADAPTATIONS IN SPECIFIC BRAIN CIRCUITRY, ANALOGOUS TO THOSE THAT UNDERLIE LONG-TERM MEMORY FORMATION. RESEARCH SPANNING THE LAST TWO DECADES HAS MADE GREAT PROGRESS IN IDENTIFYING CELLULAR AND MOLECULAR MECHANISMS THAT CONTRIBUTE TO DRUG-INDUCED CHANGES IN PLASTICITY AND BEHAVIOR. ALTERATIONS IN SYNAPTIC TRANSMISSION WITHIN THE MESOCORTICOLIMBIC AND CORTICOSTRIATAL PATHWAYS, AND CHANGES IN THE TRANSCRIPTIONAL POTENTIAL OF CELLS BY EPIGENETIC MECHANISMS ARE TWO IMPORTANT MEANS BY WHICH DRUGS OF ABUSE CAN INDUCE LASTING CHANGES IN BEHAVIOR. IN THIS REVIEW WE PROVIDE A SUMMARY OF MORE RECENT RESEARCH THAT HAS FURTHERED OUR UNDERSTANDING OF DRUG-INDUCED NEUROPLASTIC CHANGES BOTH AT THE LEVEL OF THE SYNAPSE, AND ON A TRANSCRIPTIONAL LEVEL, AND HOW THESE CHANGES MAY RELATE TO THE HUMAN DISEASE OF ADDICTION.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
10  5021  26 PERSISTENT PAIN MAINTAINS MORPHINE-SEEKING BEHAVIOR AFTER MORPHINE WITHDRAWAL THROUGH REDUCED MECP2 REPRESSION OF GLUA1 IN RAT CENTRAL AMYGDALA. AS LONG-TERM OPIOIDS ARE INCREASINGLY USED FOR CONTROL OF CHRONIC PAIN, HOW PAIN AFFECTS THE REWARDING EFFECT OF OPIOIDS AND HENCE RISK OF PRESCRIPTION OPIOID MISUSE AND ABUSE REMAINS A HEALTHCARE CONCERN AND A CHALLENGING ISSUE IN CURRENT PAIN MANAGEMENT. IN THIS STUDY, USING A RAT MODEL OF MORPHINE SELF-ADMINISTRATION, WE INVESTIGATED THE MOLECULAR MECHANISMS UNDERLYING THE IMPACT OF PAIN ON OPERANT BEHAVIOR OF MORPHINE INTAKE AND MORPHINE SEEKING BEFORE AND AFTER MORPHINE WITHDRAWAL. WE FOUND THAT RATS WITH PERSISTENT PAIN CONSUMED A SIMILAR AMOUNT OF DAILY MORPHINE TO THAT IN CONTROL RATS WITHOUT PAIN, BUT MAINTAINED THEIR LEVEL-PRESSING BEHAVIOR OF MORPHINE SEEKING AFTER ABSTINENCE OF MORPHINE AT 0.2 MG/KG, WHEREAS THIS BEHAVIOR WAS GRADUALLY DIMINISHED IN CONTROL RATS. IN THE CENTRAL NUCLEUS OF AMYGDALA (CEA), A LIMBIC STRUCTURE CRITICALLY INVOLVED IN THE AFFECTIVE DIMENSION OF PAIN, PROTEINS OF GLUA1 SUBUNITS OF GLUTAMATE AMPA RECEPTORS WERE UPREGULATED DURING MORPHINE WITHDRAWAL, AND VIRAL KNOCKDOWN OF CEA GLUA1 ELIMINATED THE MORPHINE-SEEKING BEHAVIOR IN WITHDRAWN RATS OF THE PAIN GROUP. CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT THE METHYL CPG-BINDING PROTEIN 2 (MECP2) WAS ENRICHED IN THE PROMOTER REGION OF GRIA1 ENCODING GLUA1 AND THIS ENRICHMENT WAS SIGNIFICANTLY ATTENUATED IN WITHDRAWN RATS OF THE PAIN GROUP. FURTHERMORE, VIRAL OVEREXPRESSION OF CEA MECP2 REPRESSED THE GLUA1 LEVEL AND ELIMINATED THE MAINTENANCE OF MORPHINE-SEEKING BEHAVIOR AFTER MORPHINE WITHDRAWAL. THESE RESULTS SUGGEST DIRECT MECP2 REPRESSION OF GLUA1 FUNCTION AS A LIKELY MECHANISM FOR MORPHINE-SEEKING BEHAVIOR MAINTAINED BY LONG-LASTING AFFECTIVE PAIN AFTER MORPHINE WITHDRAWAL.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
11    21  19 5-HYDROXYMETHYLCYTOSINE (5HMC) AND TEN-ELEVEN TRANSLOCATION 1-3 (TET1-3) PROTEINS IN THE DORSAL ROOT GANGLIA OF MOUSE: EXPRESSION AND DYNAMIC REGULATION IN NEUROPATHIC PAIN. EPIGENETIC MECHANISMS ARE INCREASINGLY IMPLICATED IN CHRONIC PAIN PATHOLOGY. IN THIS STUDY, WE DEMONSTRATE THAT THE NOVEL EPIGENETIC MARK 5-HYDROXYMETHYLCYTOSINE (5HMC) IS PRESENT IN DORSAL ROOT GANGLIA (DRG) NEURONS AND GLIA, AND ITS LEVELS INCREASE FOLLOWING NERVE INJURY. FURTHERMORE, WE SHOW THAT THE 5HMC-GENERATING TEN-ELEVEN TRANSLOCATION 1-3 (TET1-3) PROTEINS ARE EXPRESSED IN A CELL-TYPE SPECIFIC MANNER IN THE DRG, WITH TET3 DISPLAYING DIFFERENTIAL UPREGULATION AFTER INJURY, SUGGESTING A POTENTIAL ROLE IN NEUROPATHIC PAIN.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
12  4222  29 METHYLATION AT THE CPG ISLAND SHORE REGION UPREGULATES NR3C1 PROMOTER ACTIVITY AFTER EARLY-LIFE STRESS. EARLY-LIFE STRESS (ELS) INDUCES LONG-LASTING CHANGES IN GENE EXPRESSION CONFERRING AN INCREASED RISK FOR THE DEVELOPMENT OF STRESS-RELATED MENTAL DISORDERS. GLUCOCORTICOID RECEPTORS (GR) MEDIATE THE NEGATIVE FEEDBACK ACTIONS OF GLUCOCORTICOIDS (GC) IN THE PARAVENTRICULAR NUCLEUS (PVN) OF THE HYPOTHALAMUS AND ANTERIOR PITUITARY AND THEREFORE PLAY A KEY ROLE IN THE REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND THE ENDOCRINE RESPONSE TO STRESS. WE HERE SHOW THAT ELS PROGRAMS THE EXPRESSION OF THE GR GENE (NR3C1) BY SITE-SPECIFIC HYPERMETHYLATION AT THE CPG ISLAND (CGI) SHORE IN HYPOTHALAMIC NEURONS THAT PRODUCE CORTICOTROPIN-RELEASING HORMONE (CRH), THUS PREVENTING CRH UPREGULATION UNDER CONDITIONS OF CHRONIC STRESS. CPGS MAPPING TO THE NR3C1 CGI SHORE REGION ARE DYNAMICALLY REGULATED BY ELS AND UNDERPIN METHYLATION-SENSITIVE CONTROL OF THIS REGION'S INSULATION-LIKE FUNCTION VIA YING YANG 1 (YY1) BINDING. OUR RESULTS PROVIDE NEW INSIGHT INTO HOW A GENOMIC ELEMENT INTEGRATES EXPERIENCE-DEPENDENT EPIGENETIC PROGRAMMING OF THE COMPOSITE PROXIMAL NR3C1 PROMOTER, AND ASSIGNS AN INSULATING ROLE TO THE CGI SHORE.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
13  5976  22 TET1-DEPENDENT EPIGENETIC MODIFICATION OF BDNF EXPRESSION IN DORSAL HORN NEURONS MEDIATES NEUROPATHIC PAIN IN RATS. TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1) MEDIATES THE CONVERSION OF 5-METHYLCYTOSINE (5 MC) TO 5-HYDROXYMETHYLCYTOSINE (5 HMC), HENCE PROMOTING DNA DEMETHYLATION. ALTHOUGH RECENT STUDIES HAVE LINKED THE DNA DEMETHYLATION OF SPECIFIC GENES TO PAIN HYPERSENSITIVITY, THE ROLE OF SPINAL TET1-DEPENDENT DNA DEMETHYLATION IN NOCICEPTION HYPERSENSITIVITY DEVELOPMENT REMAINS ELUSIVE. HERE, WE REPORT CORRELATED WITH BEHAVIORAL ALLODYNIA, SPINAL NERVE LIGATION (SNL) UPREGULATED TET1 EXPRESSION IN DORSAL HORN NEURONS THAT HYDROXYLATE 5 MC TO 5 HMC AT CPG DINUCLEOTIDES IN THE BDNF PROMOTER TO PROMOTE SPINAL BDNF EXPRESSION AT DAY 7 AFTER OPERATION. FOCAL KNOCKDOWN OF SPINAL TET1 EXPRESSION DECREASED TET1 BINDING AND 5 HMC ENRICHMENT, FURTHER INCREASED 5 MC ENRICHMENT AT CPG SITES IN THE BDNF PROMOTER AND DECREASED SPINAL BDNF EXPRESSION ACCOMPANIED BY THE ALLEVIATION OF THE DEVELOPED ALLODYNIA. MOREOVER, AT DAY 7 AFTER OPERATION, SNL-ENHANCED TET1 EXPRESSION ALSO INHIBITED THE BINDING OF DNA METHYLTRANSFERASES (DNMTS, I.E., DNMT1, DNMT3A, AND DNMT3B) TO THE BDNF PROMOTER, A REQUIREMENT FOR TRANSCRIPTIONAL SILENCING BY CATALYSING 5-CYTOSINE (5C) TO 5 MC. TOGETHER, THESE DATA SUGGEST AT CPG SITES OF THE BDNF PROMOTER, SNL-ENHANCED TET1 EXPRESSION PROMOTES DNA DEMETHYLATION BOTH BY CONVERTING 5 MC TO 5 HMC AND INHIBITING DNMT BINDING TO REGULATE SPINAL BDNF EXPRESSION, HENCE CONTRIBUTING TO BEHAVIORAL ALLODYNIA DEVELOPMENT.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
14  2667  35 ESTROGEN AND SEROTONIN ENHANCE STRESS-INDUCED VISCERAL HYPERSENSITIVITY IN FEMALE RATS BY UP-REGULATING BRAIN-DERIVED NEUROTROPHIC FACTOR IN SPINAL CORD. BACKGROUND: WE PREVIOUSLY REPORTED THAT FEMALE OFFSPRING OF DAMS SUBJECTED TO CHRONIC PRENATAL STRESS (CPS) DEVELOP ENHANCED VISCERAL HYPERSENSITIVITY (VHS) FOLLOWING EXPOSURE TO CHRONIC STRESS IN ADULT LIFE THAT IS MEDIATED BY UP-REGULATION OF SPINAL CORD BDNF. THE AIMS OF THIS STUDY WERE TO EXAMINE THE ROLES OF ESTROGEN RECEPTOR ALPHA (ERALPHA) AND AN INCREASE IN SPINAL SEROTONIN SIGNALING IN PROMOTING THIS ENHANCED VHS IN FEMALE RATS AND UP-REGULATION OF SPINAL CORD BDNF TRANSCRIPTION. METHODS: PREGNANT DAMS WERE EXPOSED TO CHRONIC STRESS FROM E11 UNTIL DELIVERY. AT 8 WEEKS, A CHRONIC ADULT STRESS (CAS) PROTOCOL WAS APPLIED FOR NINE DAYS. KEY RESULTS: OVARIECTOMY BEFORE CAS OR TREATMENT WITH LETROZOLE BEFORE AND DURING CAS SIGNIFICANTLY PREVENTED THE DEVELOPMENT OF ENHANCED VHS IN FEMALE CPS+CAS RATS. INTRATHECAL APPLICATION OF ERALPHA SIRNA SIGNIFICANTLY REDUCED VHS, DECREASED LUMBAR-SACRAL SPINAL CORD EXPRESSION OF BOTH ERALPHA AND BDNF, AND REVERSED PRO-TRANSCRIPTIONAL EPIGENETIC MODIFICATIONS AT BDNF PROMOTER LX. CEREBROSPINAL FLUID SEROTONIN LEVELS AND 5HT3A RECEPTOR EXPRESSION IN THE LS SPINAL CORD WERE BOTH SIGNIFICANTLY INCREASED IN FEMALE CPS+CAS RATS. DURING CAS, INTRATHECAL INFUSION OF ALOSETRON SIGNIFICANTLY DECREASED VHS, REDUCED BDNF AND ERALPHA EXPRESSION IN THE LS SPINAL CORD, AND ATTENUATED RNA POL II AND ERALPHA BINDING TO THE BNDF CORE PROMOTER IX. CONCLUSIONS & INFERENCES: SEROTONIN-MEDIATED ACTIVATION OF 5HT3A RECEPTORS IN THE SPINAL CORD DRIVES THE DEVELOPMENT OF ENHANCED FEMALE-SPECIFIC VHS IN OUR TWO HIT CPS+CAS THROUGH UP-REGULATION OF SPINAL CORD ERALPHA.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
15   345  31 ALTERED BRAIN EXPRESSION OF DNA METHYLATION AND HYDROXYMETHYLATION EPIGENETIC ENZYMES IN A RAT MODEL OF NEUROPATHIC PAIN. THE ROLE OF EPIGENETICS IN CHRONIC PAIN AT THE SUPRASPINAL LEVEL IS YET TO BE FULLY CHARACTERIZED. DNA HISTONE METHYLATION IS CRUCIALLY REGULATED BY DE NOVO METHYLTRANSFERASES (DNMT1-3) AND TEN-ELEVEN TRANSLOCATION DIOXYGENASES (TET1-3). EVIDENCE HAS SHOWN THAT METHYLATION MARKERS ARE ALTERED IN DIFFERENT CNS REGIONS RELATED TO NOCICEPTION, NAMELY THE DORSAL ROOT GANGLIA, THE SPINAL CORD, AND DIFFERENT BRAIN AREAS. DECREASED GLOBAL METHYLATION WAS FOUND IN THE DRG, THE PREFRONTAL CORTEX, AND THE AMYGDALA, WHICH WAS ASSOCIATED WITH DECREASED DNMT1/3A EXPRESSION. IN CONTRAST, INCREASED METHYLATION LEVELS AND MRNA LEVELS OF TET1 AND TET3 WERE LINKED TO AUGMENTED PAIN HYPERSENSITIVITY AND ALLODYNIA IN INFLAMMATORY AND NEUROPATHIC PAIN MODELS. SINCE EPIGENETIC MECHANISMS MAY BE RESPONSIBLE FOR THE REGULATION AND COORDINATION OF VARIOUS TRANSCRIPTIONAL MODIFICATIONS DESCRIBED IN CHRONIC PAIN STATES, WITH THIS STUDY, WE AIMED TO EVALUATE THE FUNCTIONAL ROLE OF TET1-3 AND DNMT1/3A GENES IN NEUROPATHIC PAIN IN SEVERAL BRAIN AREAS. IN A SPARED NERVE INJURY RAT MODEL OF NEUROPATHIC PAIN, 21 DAYS AFTER SURGERY, WE FOUND INCREASED TET1 EXPRESSION IN THE MEDIAL PREFRONTAL CORTEX AND DECREASED EXPRESSION IN THE CAUDATE-PUTAMEN AND THE AMYGDALA; TET2 WAS UPREGULATED IN THE MEDIAL THALAMUS; TET3 MRNA LEVELS WERE REDUCED IN THE MEDIAL PREFRONTAL CORTEX AND THE CAUDATE-PUTAMEN; AND DNMT1 WAS DOWNREGULATED IN THE CAUDATE-PUTAMEN AND THE MEDIAL THALAMUS. NO STATISTICALLY SIGNIFICANT CHANGES IN EXPRESSION WERE OBSERVED WITH DNMT3A. OUR RESULTS SUGGEST A COMPLEX FUNCTIONAL ROLE FOR THESE GENES IN DIFFERENT BRAIN AREAS IN THE CONTEXT OF NEUROPATHIC PAIN. THE NOTION OF DNA METHYLATION AND HYDROXYMETHYLATION BEING CELL-TYPE SPECIFIC AND NOT TISSUE SPECIFIC, AS WELL AS THE POSSIBILITY OF CHRONOLOGICALLY DIFFERENTIAL GENE EXPRESSION AFTER THE ESTABLISHMENT OF NEUROPATHIC OR INFLAMMATORY PAIN MODELS, OUGHT TO BE ADDRESSED IN FUTURE STUDIES.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
16   243  26 ADOLESCENT CHRONIC INTERMITTENT TOLUENE INHALATION DYNAMICALLY REGULATES THE TRANSCRIPTOME AND NEURONAL METHYLOME WITHIN THE RAT MEDIAL PREFRONTAL CORTEX. INHALANTS CONTAINING THE VOLATILE SOLVENT TOLUENE ARE MISUSED TO INDUCE EUPHORIA OR INTOXICATION. INHALANT ABUSE IS MOST COMMON DURING ADOLESCENCE AND CAN RESULT IN COGNITIVE IMPAIRMENTS DURING AN IMPORTANT MATURATIONAL PERIOD. DESPITE EVIDENCE SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY UNDERPIN THE COGNITIVE EFFECTS OF INHALANTS, NO STUDIES TO DATE HAVE THOROUGHLY INVESTIGATED TOLUENE-INDUCED REGULATION OF THE TRANSCRIPTOME OR DISCRETE EPIGENETIC MODIFICATIONS WITHIN THE BRAIN. TO ADDRESS THIS, WE INVESTIGATED EFFECTS OF ADOLESCENT CHRONIC INTERMITTENT TOLUENE (CIT) INHALATION ON GENE EXPRESSION AND DNA METHYLATION PROFILES WITHIN THE RAT MEDIAL PREFRONTAL CORTEX (MPFC), WHICH UNDERGOES MATURATION THROUGHOUT ADOLESCENCE AND HAS BEEN IMPLICATED IN TOLUENE-INDUCED COGNITIVE DEFICITS. EMPLOYING BOTH RNA-SEQ AND GENOME-WIDE METHYL CPG BINDING DOMAIN (MBD) ULTRA-SEQ ANALYSIS, WE DEMONSTRATE THAT ADOLESCENT CIT INHALATION (10 000 PPM FOR 1 H/DAY, 3 DAYS/WEEK FOR 4 WEEKS) INDUCES BOTH TRANSIENT AND PERSISTENT CHANGES TO THE TRANSCRIPTOME AND DNA METHYLOME WITHIN THE RAT MPFC FOR AT LEAST 2 WEEKS FOLLOWING TOLUENE EXPOSURE. WE DEMONSTRATE FOR THE FIRST TIME THAT ADOLESCENT CIT EXPOSURE RESULTS IN DYNAMIC REGULATION OF THE MPFC TRANSCRIPTOME LIKELY RELATING TO ACUTE INFLAMMATORY RESPONSES AND PERSISTENT DEFICITS IN SYNAPTIC PLASTICITY. THESE ADAPTATIONS MAY CONTRIBUTE TO THE COGNITIVE DEFICITS ASSOCIATED WITH CHRONIC TOLUENE EXPOSURE AND PROVIDE NOVEL MOLECULAR TARGETS FOR PREVENTING LONG-TERM NEUROPHYSIOLOGICAL ABNORMALITIES FOLLOWING CHRONIC TOLUENE INHALATION.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
17  2012  24 EPIGENETIC BASIS OF OPIATE SUPPRESSION OF BDNF GENE EXPRESSION IN THE VENTRAL TEGMENTAL AREA. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS A CRUCIAL ROLE IN MODULATING NEURAL AND BEHAVIORAL PLASTICITY TO DRUGS OF ABUSE. WE FOUND A PERSISTENT DOWNREGULATION OF EXON-SPECIFIC BDNF EXPRESSION IN THE VENTRAL TEGMENTAL AREA (VTA) IN RESPONSE TO CHRONIC OPIATE EXPOSURE, WHICH WAS MEDIATED BY SPECIFIC EPIGENETIC MODIFICATIONS AT THE CORRESPONDING BDNF GENE PROMOTERS. EXPOSURE TO CHRONIC MORPHINE INCREASED STALLING OF RNA POLYMERASE II AT THESE BDNF PROMOTERS IN VTA AND ALTERED PERMISSIVE AND REPRESSIVE HISTONE MODIFICATIONS AND OCCUPANCY OF THEIR REGULATORY PROTEINS AT THE SPECIFIC PROMOTERS. FURTHERMORE, WE FOUND THAT MORPHINE SUPPRESSED BINDING OF PHOSPHO-CREB (CAMP RESPONSE ELEMENT BINDING PROTEIN) TO BDNF PROMOTERS IN VTA, WHICH RESULTED FROM ENRICHMENT OF TRIMETHYLATED H3K27 AT THE PROMOTERS, AND THAT DECREASED NURR1 (NUCLEAR RECEPTOR RELATED-1) EXPRESSION ALSO CONTRIBUTED TO BDNF REPRESSION AND ASSOCIATED BEHAVIORAL PLASTICITY TO MORPHINE. OUR FINDINGS SUGGEST PREVIOUSLY UNKNOWN EPIGENETIC MECHANISMS OF MORPHINE-INDUCED MOLECULAR AND BEHAVIORAL NEUROADAPTATIONS.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
18  3986  29 LONG-TERM OVARIECTOMY INCREASES BDNF GENE METHYLATION STATUS IN MOUSE HIPPOCAMPUS. ESTRADIOL (E) HAS BEEN SUGGESTED TO HAVE A NEUROPROTECTIVE EFFECT IN YOUNG ANIMALS BUT HAS NEUTRAL OR HARMFUL EFFECTS WHEN IT IS ADMINISTERED TO AGED ANIMALS. IN THE PRESENT STUDY, WE DETERMINED WHETHER THE POST-OVARIECTOMY (POST-OVX) TIMEFRAME ELAPSED BEFORE THE INITIATION OF CHRONIC E TREATMENT IS CRITICAL FOR THE ESTROGENIC INDUCTION OF NEUROTROPHINS (BRAIN-DERIVED NEUROTROPHIC FACTOR, BDNF, AND SYNAPTOPHYSIN, SYN) IN THE RODENT HIPPOCAMPUS. ADULT MICE WERE OVX AND, A SHORT PERIOD (SHORT-TERM E (STE) ANIMALS) OR A LONG PERIOD (LONG-TERM E (LTE) ANIMALS) AFTER THE OVX, WERE DAILY TREATED WITH E. CONTROL ANIMALS WERE TREATED WITH SESAME OIL (SHORT-TERM CONTROL (STC) AND LONG-TERM CONTROL (LTC) ANIMALS). PROTEIN EXPRESSION WAS DETERMINED USING AN IMMUNOHISTOCHEMICAL APPROACH. TRANSCRIPTIONAL ACTIVITY IN THE HIPPOCAMPUS OF INDIVIDUAL BDNF PROMOTERS WAS ASSESSED BY REAL-TIME QUANTITATIVE RT-PCR, AND THE METHYLATION LEVELS OF REGULATORY REGIONS WERE ANALYZED BY METHYLATION-SPECIFIC PCR AND COMBINED BISULFITE RESTRICTION ANALYSIS. STE ANIMALS SHOWED INCREASED BDNF AND SYN PROTEIN EXPRESSION AND A HIGHER ACTIVITY OF BDNF II, IV, AND V PROMOTERS. IN CONTRAST, LTE ANIMALS DID NOT SHOW E INDUCTION OF NEUROTROPHINS. IN THESE ANIMALS, THE METHYLATION LEVELS OF REGULATORY SEQUENCES OF THE BDNF WERE HIGHER THAN IN THE STE ANIMALS IN A CPG ISLAND OF PROMOTER V AND IN THE CRE REGULATORY SITE LOCATED IN PROMOTER IV. WITH THIS EXPERIMENT, WE DETERMINED THAT A PROLONGED PERIOD OF HYPOESTROGENICITY DISRUPTS THE E-INDUCTION OF NEUROTROPHINS, AND WE POSTULATED THAT DNA METHYLATION IS ONE OF THE EPIGENETIC MECHANISMS THAT COULD EXPLAIN THE E-INSENSITIVITY OF THE BDNF AFTER A LONG PERIOD POST-OVX.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
19  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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
20  6551  26 TRANSGENERATIONAL BLUNTING OF MORPHINE-INDUCED CORTICOSTERONE SECRETION IS ASSOCIATED WITH DYSREGULATED GENE EXPRESSION IN MALE OFFSPRING. A NUMBER OF PARENTAL EXPERIENCES, EVEN WHEN OCCURRING PRIOR TO CONCEPTION, HAVE BEEN SHOWN TO INDUCE TRANSGENERATIONAL EFFECTS BEYOND THE FIRST GENERATION. IN THE CASE OF EXPOSURE TO DRUGS OF ABUSE, STUDIES IN RODENTS SUGGEST THAT OFFSPRING DEMONSTRATE SIGNIFICANT DIFFERENCES IN HOW THEY RESPOND TO THE DRUG TO WHICH THEIR PARENT WAS EXPOSED. WE HAVE PREVIOUSLY OBSERVED SIGNIFICANT ALTERATIONS IN MORPHINE ANALGESIA, CONDITIONED PLACE PREFERENCE AND SELF-ADMINISTRATION IN THE OFFSPRING OF FEMALES EXPOSED TO MORPHINE DURING ADOLESCENT DEVELOPMENT. IN ADDITION TO EFFECTS ON PAIN PERCEPTION AND REWARD, MORPHINE ALSO MODULATES THE HYPOTHALAMIC PITUITARY ADRENAL (HPA) AXIS. THE PURPOSE OF THE CURRENT STUDY WAS TO DETERMINE WHETHER FEMALE ADOLESCENT MORPHINE EXPOSURE RESULTS IN TRANSGENERATIONAL EFFECTS ON REGULATION OF THE HPA AXIS BY MORPHINE IN FUTURE GENERATIONS. ADOLESCENT MORPHINE WAS ADMINISTERED TO FEMALE SPRAGUE DAWLEY RATS USING A 10 DAY, ESCALATING DOSE REGIMEN OF MORPHINE (5-25 MG/KG; FROM 30 TO 39 DAYS OF AGE). CONTROL ANIMALS RECEIVED SALINE. BOTH SALINE AND MORPHINE EXPOSED FEMALES (SAL-F0 AND MOR-F0, RESPECTIVELY) WERE MATED WITH DRUG NAIVE MALES BEGINNING AT LEAST 3 WEEKS AFTER THE FINAL INJECTION. PLASMA CORTICOSTERONE LEVELS WERE MEASURED IN MALE AND FEMALE OFFSPRING (F1) DURING ADULTHOOD FOLLOWING 0, 0.1, OR 10 MG/KG MORPHINE. IN ADDITION, EXPRESSION OF CORTICOTROPIN RELEASING HORMONE (CRH) AND MU OPIOID RECEPTOR (OPRM1) IN THE PARAVENTRICULAR NUCLEUS (PVN) WERE MEASURED USING QUANTITATIVE PCR. MOR-F1 MALES, BUT NOT FEMALES, HAD BLUNTED MORPHINE-INDUCED CORTICOSTERONE SECRETION. THIS EFFECT WAS SPECIFIC TO OFFSPRING FROM FEMALES EXPOSED TO MORPHINE DURING ADOLESCENCE AS THOSE EXPOSED DURING ADULTHOOD PRODUCED OFFSPRING IN WHICH THE EFFECT WAS ABSENT. IN ADDITION, MOR-F1 MALES HAD SIGNIFICANTLY LOWER LEVELS OF PVN CRH FOLLOWING SALINE. THESE EFFECTS WERE NOT DRIVEN BY PVN OPRM1 IN THE F1 MALES AS THERE WERE NO DIFFERENCES BASED ON MATERNAL ADOLESCENT EXPOSURE. TO DETERMINE THE PERSISTENCE OF THE BLUNTED MORPHINE-INDUCED CORTICOSTERONE EFFECT, SAL-F2 AND MOR-F2 MALES WERE EXAMINED. BLUNTED MORPHINE-INDUCED CORTICOSTERONE SECRETION EXTENDED INTO THE MOR-F2 GENERATION, AS WELL AS EFFECTS ON CRH. IN ADDITION, THERE WAS ADDITIONAL DYSREGULATION OFOPRM1 EXPRESSION IN THE PVN IN MOR-F2 COMPARED WITH SAL-F2 MALES. THESE FINDINGS SUGGEST THAT SEX-SPECIFIC ALTERATIONS IN OPIOID-MEDIATED REGULATION OF THE HPA AXIS ARE TRANSGENERATIONALLY TRANSMITTED FOR AT LEAST TWO GENERATIONS FOLLOWING FEMALE ADOLESCENT MORPHINE EXPOSURE. THESE EFFECTS MAY PLAY A ROLE IN THE PREVIOUSLY OBSERVED CHANGES IN MORPHINE ANALGESIA AND REWARD-RELATED BEHAVIORS OBSERVED IN THIS PHENOTYPE. IN ADDITION, ALTERATIONS IN HPA FUNCTIONING SUCH AS THESE MAY PLAY A BROAD ROLE IN TRANSGENERATIONAL EPIGENETIC TRANSMISSION.	2018