1 36 126 A CHROMATIN ASSAY FOR HUMAN BRAIN TISSUE. CHRONIC NEUROPSYCHIATRIC ILLNESSES SUCH AS SCHIZOPHRENIA, BIPOLAR DISEASE AND AUTISM ARE THOUGHT TO RESULT FROM A COMBINATION OF GENETIC AND ENVIRONMENTAL FACTORS THAT MIGHT RESULT IN EPIGENETIC ALTERATIONS OF GENE EXPRESSION AND OTHER MOLECULAR PATHOLOGY. TRADITIONALLY, HOWEVER, EXPRESSION STUDIES IN POSTMORTEM BRAIN WERE CONFINED TO QUANTIFICATION OF MRNA OR PROTEIN. THE LIMITATIONS ENCOUNTERED IN POSTMORTEM BRAIN RESEARCH SUCH AS VARIABILITIES IN AUTOLYSIS TIME AND TISSUE INTEGRITIES ARE ALSO LIKELY TO IMPACT ANY STUDIES OF HIGHER ORDER CHROMATIN STRUCTURES. HOWEVER, THE NUCLEOSOMAL ORGANIZATION OF GENOMIC DNA INCLUDING DNA:CORE HISTONE BINDING - APPEARS TO BE LARGELY PRESERVED IN REPRESENTATIVE SAMPLES PROVIDED BY VARIOUS BRAIN BANKS. THEREFORE, IT IS POSSIBLE TO STUDY THE METHYLATION PATTERN AND OTHER COVALENT MODIFICATIONS OF THE CORE HISTONES AT DEFINED GENOMIC LOCI IN POSTMORTEM BRAIN. HERE, WE PRESENT A SIMPLIFIED NATIVE CHROMATIN IMMUNOPRECIPITATION (NCHIP) PROTOCOL FOR FROZEN (NEVER-FIXED) HUMAN BRAIN SPECIMENS. STARTING WITH MICROCOCCAL NUCLEASE DIGESTION OF BRAIN HOMOGENATES, NCHIP FOLLOWED BY QPCR CAN BE COMPLETED WITHIN THREE DAYS. THE METHODOLOGY PRESENTED HERE SHOULD BE USEFUL TO ELUCIDATE EPIGENETIC MECHANISMS OF GENE EXPRESSION IN NORMAL AND DISEASED HUMAN BRAIN. 2008 2 4641 45 NEURONAL NUCLEI ISOLATION FROM HUMAN POSTMORTEM BRAIN TISSUE. NEURONS IN THE HUMAN BRAIN BECOME POSTMITOTIC LARGELY DURING PRENATAL DEVELOPMENT, AND THUS MAINTAIN THEIR NUCLEI THROUGHOUT THE FULL LIFESPAN. HOWEVER, LITTLE IS KNOWN ABOUT CHANGES IN NEURONAL CHROMATIN AND NUCLEAR ORGANIZATION DURING THE COURSE OF DEVELOPMENT AND AGING, OR IN CHRONIC NEUROPSYCHIATRIC DISEASE. HOWEVER, TO DATE MOST CHROMATIN AND DNA BASED ASSAYS (OTHER THAN FISH) LACK SINGLE CELL RESOLUTION. TO THIS END, THE CONSIDERABLE CELLULAR HETEROGENEITY OF BRAIN TISSUE POSES A SIGNIFICANT LIMITATION, BECAUSE TYPICALLY VARIOUS SUBPOPULATIONS OF NEURONS ARE INTERMINGLED WITH DIFFERENT TYPES OF GLIA AND OTHER NON-NEURONAL CELLS. ONE POSSIBLE SOLUTION WOULD BE TO GROW CELL-TYPE SPECIFIC CULTURES, BUT MOST CNS CELLS, INCLUDING NEURONS, ARE EX VIVO SUSTAINABLE, AT BEST, FOR ONLY A FEW WEEKS AND THUS WOULD PROVIDE AN INCOMPLETE MODEL FOR EPIGENETIC MECHANISMS POTENTIALLY OPERATING ACROSS THE FULL LIFESPAN. HERE, WE PROVIDE A PROTOCOL TO EXTRACT AND PURIFY NUCLEI FROM FROZEN (NEVER FIXED) HUMAN POSTMORTEM BRAIN. THE METHOD INVOLVES EXTRACTION OF NUCLEI IN HYPOTONIC LYSIS BUFFER, FOLLOWED BY ULTRACENTRIFUGATION AND IMMUNOTAGGING WITH ANTI-NEUN ANTIBODY. LABELED NEURONAL NUCLEI ARE THEN COLLECTED SEPARATELY USING FLUORESCENCE-ACTIVATED SORTING. THIS METHOD SHOULD BE APPLICABLE TO ANY BRAIN REGION IN A WIDE RANGE OF SPECIES AND SUITABLE FOR CHROMATIN IMMUNOPRECIPITATION STUDIES WITH SITE- AND MODIFICATION-SPECIFIC ANTI-HISTONE ANTIBODIES, AND FOR DNA METHYLATION AND OTHER ASSAYS. 2008 3 4093 32 MATERNAL SEPARATION FOLLOWED BY CHRONIC MILD STRESS IN ADULTHOOD IS ASSOCIATED WITH CONCERTED EPIGENETIC REGULATION OF AP-1 COMPLEX GENES. DEPRESSION IS ONE OF THE MOST PREVALENT MENTAL DISEASES WORLDWIDE. PATIENTS WITH PSYCHIATRIC DISEASES OFTEN HAVE A HISTORY OF CHILDHOOD NEGLECT, INDICATING THAT EARLY-LIFE EXPERIENCES PREDISPOSE TO PSYCHIATRIC DISEASES IN ADULTHOOD. TWO STRONG MODELS WERE USED IN THE PRESENT STUDY: THE MATERNAL SEPARATION/EARLY DEPRIVATION MODEL (MS) AND THE CHRONIC MILD STRESS MODEL (CMS). IN BOTH MODELS, WE FOUND CHANGES IN THE EXPRESSION OF A NUMBER OF GENES SUCH AS CREB AND NPY. STRIKINGLY, THERE WAS A CLEAR REGULATION OF EXPRESSION OF FOUR GENES INVOLVED IN THE AP-1 COMPLEX: C-FOS, C-JUN, FOSB, AND JUN-B. INTERESTINGLY, DIFFERENT EXPRESSION LEVELS WERE OBSERVED DEPENDING ON THE MODEL, WHEREAS THE COMBINATION OF THE MODELS RESULTED IN A NORMAL LEVEL OF GENE EXPRESSION. THE EFFECTS OF MS AND CMS ON GENE EXPRESSION WERE ASSOCIATED WITH DISTINCT HISTONE METHYLATION/ACETYLATION PATTERNS OF ALL FOUR GENES. THE EPIGENETIC CHANGES, LIKE GENE EXPRESSION, WERE ALSO DEPENDENT ON THE SPECIFIC STRESSOR OR THEIR COMBINATION. THE OBTAINED RESULTS SUGGEST THAT SINGLE LIFE EVENTS LEAVE A MARK ON GENE EXPRESSION AND THE EPIGENETIC SIGNATURE OF GENE PROMOTERS, BUT A COMBINATION OF DIFFERENT STRESSORS AT DIFFERENT LIFE STAGES CAN FURTHER CHANGE GENE EXPRESSION THROUGH EPIGENETIC FACTORS, POSSIBLY CAUSING THE LONG-LASTING ADVERSE EFFECTS OF STRESS. 2021 4 2119 30 EPIGENETIC HISTONE MODIFICATION REGULATES DEVELOPMENTAL LEAD EXPOSURE INDUCED HYPERACTIVITY IN RATS. LEAD (PB) EXPOSURE WAS COMMONLY CONSIDERED AS A HIGH ENVIRONMENTAL RISK FACTOR FOR THE DEVELOPMENT OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER (ADHD). HOWEVER, THE MOLECULAR BASIS OF THIS PATHOLOGICAL PROCESS STILL REMAINS ELUSIVE. IN LIGHT OF THE ROLE OF EPIGENETICS IN MODULATING THE NEUROLOGICAL DISEASE AND THE CAUSATIVE ENVIRONMENT, THE ALTERATIONS OF HISTONE MODIFICATIONS IN THE HIPPOCAMPUS OF RATS EXPOSED BY VARIOUS DOSES OF LEAD, ALONG WITH CONCOMITANT BEHAVIORAL DEFICITS, WERE INVESTIGATED IN THIS STUDY. ACCORDING TO THE FREE AND FORCED OPEN FIELD TEST, THERE SHOWED THAT IN A DOSAGE-DEPENDENT MANNER, LEAD EXPOSURE COULD RESULT IN THE INCREASED LOCOMOTOR ACTIVITY OF RATS, THAT IS, HYPERACTIVITY: A SUBTYPE OF ADHD. WESTERN BLOTTING ASSAYS REVEALED THAT THE LEVELS OF HISTONE ACETYLATION INCREASED SIGNIFICANTLY IN THE HIPPOCAMPUS BY CHRONIC LEAD EXPOSURE, WHILE NO DRAMATIC CHANGES WERE DETECTED IN TERMS OF EXPRESSION YIELDS OF ADHD-RELATED DOPAMINERGIC PROTEINS, INDICATING THAT HISTONE ACETYLATION PLAYS ESSENTIAL ROLES IN THIS TOXICANT-INVOLVED PATHOGENESIS. IN ADDITION, THE INCREASED LEVEL OF HISTONE ACETYLATION MIGHT BE ATTRIBUTED TO THE ENZYMATIC ACTIVITY OF P300, A TYPICAL HISTONE ACETYLTRANSFERASE, AS THE TRANSCRIPTIONAL LEVEL OF P300 WAS SIGNIFICANTLY INCREASED UPON HIGHER-DOSE PB EXPOSURE. IN SUMMARY, THIS STUDY FIRST DISCOVERED THE EPIGENETIC MECHANISM BRIDGING THE ENVIRONMENTAL INFLUENCE (PB) AND THE DISEASE ITSELF (ADHD) IN THE HISTONE MODIFICATION LEVEL, PAVING THE WAY FOR THE COMPREHENSIVE UNDERSTANDING OF ADHD'S ETIOLOGY AND IN FURTHER STEPS, ESTABLISHING THE THERAPY STRATEGY OF THIS WIDESPREAD NEUROLOGICAL DISORDER. 2014 5 4370 28 MIRNAS AND THEIR ROLE IN THE CORRELATION BETWEEN SCHIZOPHRENIA AND CANCER (REVIEW). SCHIZOPHRENIA (SZ) AND CANCER (CA) HAVE A BROAD SPECTRUM OF CLINICAL PHENOTYPES AND A COMPLEX BIOLOGICAL BACKGROUND, IMPLICATING A LARGE NUMBER OF GENETIC AND EPIGENETIC FACTORS. SZ IS A CHRONIC NEURODEVELOPMENTAL DISORDER SIGNIFIED BY AN INCREASE IN THE EXPRESSION OF APOPTOTIC MOLECULAR SIGNALS, WHEREAS CA IS CONVERSELY CHARACTERIZED BY AN INCREASE IN APPROPRIATE MOLECULAR SIGNALING THAT STIMULATES UNCONTROLLED CELL PROLIFERATION. THE RATHER LOW RISK OF DEVELOPING CA IN PATIENTS SUFFERING FROM SZ IS A HYPOTHESIS THAT IS STILL UNDER DEBATE. RECENT EVIDENCE HAS INDICATED THAT MICRORNAS (MIRNAS OR MIRS), A LARGE GROUP OF SMALL NON?CODING OLIGONOUCLEOTIDES, MAY PLAY A SIGNIFICANT ROLE IN THE DEVELOPMENT OF CA AND MAJOR PSYCHIATRIC DISORDERS, SUCH AS SZ, BIPOLAR DISORDER, AUTISM SPECTRUM DISORDERS, SUICIDALITY AND DEPRESSION, THROUGH THEIR INTERFERENCE WITH THE EXPRESSION OF MULTIPLE GENES. FOR INSTANCE, THE POSSIBLE ROLE OF LET?7, MIR?98 AND MIR?183 AS BIOMARKERS FOR CA AND SZ WAS INVESTIGATED IN OUR PREVIOUS RESEARCH STUDIES. THEREFORE, FURTHER INVESTIGATIONS ON THE EXPRESSION PROFILES OF THESE REGULATORY, SMALL RNA MOLECULES AND THE MOLECULAR PATHWAYS THROUGH WHICH THEY EXERT THEIR CONTROL MAY PROVIDE A PLAUSIBLE EXPLANATION AS TO WHETHER THERE IS A CORRELATION BETWEEN PSYCHIATRIC DISORDERS AND LOW RISK OF DEVELOPING CA. 2016 6 6268 26 THE NEUROEPIGENOME: IMPLICATIONS OF CHEMICAL AND PHYSICAL MODIFICATIONS OF GENOMIC DNA IN SCHIZOPHRENIA. SCHIZOPHRENIA IS A CHRONIC MENTAL ILLNESS WITH A SUBSTANTIAL GENETIC COMPONENT. TO UNFOLD THE COMPLEX ETIOLOGY OF SCHIZOPHRENIA, IT IS IMPORTANT TO UNDERSTAND THE INTERPLAY BETWEEN GENETIC AND NONGENETIC FACTORS. GENETIC FACTORS INVOLVE VARIATION IN THE DNA SEQUENCES OF PROTEIN-CODING GENES, WHICH DIRECTLY CONTRIBUTE TO PHENOTYPIC TRAITS, AND VARIATION IN NONCODING SEQUENCES, WHICH COMPRISE 98% OF THE GENOME AND CONTAIN DNA ELEMENTS KNOWN TO PLAY A ROLE IN REGULATING GENE EXPRESSION. THE EPIGENOME REFERS TO THE CHEMICAL MODIFICATIONS ON BOTH DNA AND THE STRUCTURAL PROTEINS THAT PACKAGE DNA INTO THE NUCLEUS, WHICH TOGETHER REGULATE GENE EXPRESSION IN SPECIFIC CELL TYPES, CONDITIONS, AND DEVELOPMENTAL STAGES. THE DYNAMIC NATURE OF THE EPIGENOME MAKES IT AN IDEAL TOOL TO INVESTIGATE THE RELATIONSHIP BETWEEN INHERITED GENETIC MUTATIONS ASSOCIATED WITH SCHIZOPHRENIA AND ALTERED GENE REGULATION THROUGHOUT THE COURSE OF BRAIN DEVELOPMENT. IN THIS REVIEW, WE FOCUS ON THE CURRENT UNDERSTANDING OF THE ROLE OF EPIGENETIC MARKS AND THEIR THREE-DIMENSIONAL NUCLEAR ORGANIZATION IN THE DEVELOPMENTAL TRAJECTORY OF DISTINCT BRAIN CELL TYPES TO DECIPHER THE COMPLEX GENE REGULATORY MECHANISMS THAT ARE DISRUPTED IN SCHIZOPHRENIA. 2022 7 405 32 ANALYSIS OF EPIGENETIC MECHANISMS REGULATING OPIOID RECEPTOR GENE TRANSCRIPTION. OPIOID DRUGS ARE GENERALLY USED FOR MODERATE AND SEVERE PAIN REDUCTIONS WHICH ACT THROUGH OPIOID RECEPTORS. STUDIES ON TRANSCRIPTIONAL REGULATION OF OPIOID RECEPTORS ARE STILL INVALUABLE BECAUSE NOT ONLY TRANSCRIPTION IS THE FIRST STEP TO PRODUCE PROTEIN PRODUCTS IN CELLS, BUT THE RECEPTOR TRANSCRIPTION LEVELS ALSO AFFECT THE PAIN REDUCTION BY OPIOIDS, AS OBSERVED IN STUDIES OF HETEROZYGOUS OPIOID RECEPTOR KNOCKOUT MICE.THERE ARE GROWING EVIDENCES THAT EPIGENETIC REGULATION HAS PLAYED SIGNIFICANT ROLES IN TRANSCRIPTIONAL REGULATION OF GENES, INCLUDING OPIOID RECEPTORS. IN GENERAL, EPIGENETIC MECHANISMS INCLUDE THREE MAIN REGULATORY FACTORS: DNA METHYLATION, CHROMATIN MODIFICATION, AND NONCODING RNAS (SUCH AS MICRORNA). FROM PREVIOUS STUDIES OF OURS AND OTHERS ON OPIOID RECEPTORS, THOSE EPIGENETIC FACTORS WERE CLEARLY INVOLVED IN REGULATING OPIOID RECEPTOR EXPRESSION IN VIVO AND IN VITRO. IN THIS CHAPTER, AMONG THOSE THREE TECHNIQUES WE DESCRIBE MORE DETAILS OF DNA METHYLATION METHODS BECAUSE OF EMERGING CONCEPTS OF DNA METHYLATION WITH THE RECENT DISCOVERY OF 5-HYDROXYMETHYLCYTOSINE CONVERTING ENZYME, TET1. ANOTHER ANALYTICAL METHOD OF THE EPIGENETIC FACTORS, CHROMATIN MODIFICATION, WILL BE DESCRIBED BRIEFLY AND INFORMATION OF ANALYZING NONCODING RNAS IS BRIEFLY MENTIONED IN SUBHEADING 1. 2015 8 1796 28 EFFECT OF GERM-FREE STATUS ON TRANSCRIPTIONAL PROFILES IN THE NUCLEUS ACCUMBENS AND TRANSCRIPTOMIC RESPONSE TO CHRONIC MORPHINE. OPIOID USE DISORDER IS A PUBLIC HEALTH CRISIS THAT CAUSES TREMENDOUS SUFFERING FOR PATIENTS AS WELL AS SUBSTANTIAL SOCIAL AND ECONOMIC COSTS FOR SOCIETY. THERE ARE CURRENTLY AVAILABLE TREATMENTS FOR PATIENTS WITH OPIOID USE DISORDER, BUT THEY REMAIN INTOLERABLE OR INEFFECTIVE FOR MANY. THUS THE NEED TO DEVELOP NEW AVENUES FOR THERAPEUTICS DEVELOPMENT IN THIS SPACE IS GREAT. SUBSTANTIAL WORK IN MODELS OF SUBSTANCE USE DISORDERS, INCLUDING OPIOID USE DISORDER, DEMONSTRATES THAT PROLONGED EXPOSURE TO DRUGS OF ABUSE LEADS TO MARKED TRANSCRIPTIONAL AND EPIGENETIC DYSREGULATION IN LIMBIC SUBSTRUCTURES. IT IS WIDELY BELIEVED THAT THESE CHANGES IN GENE REGULATION IN RESPONSE TO DRUGS ARE A KEY DRIVING FACTOR IN THE PERPETUATION OF DRUG TAKING AND SEEKING BEHAVIORS. THUS, DEVELOPMENT OF INTERVENTIONS THAT COULD SHAPE TRANSCRIPTIONAL REGULATION IN RESPONSE TO DRUGS OF ABUSE WOULD BE OF HIGH VALUE. OVER THE PAST DECADE THERE HAS BEEN A SURGE IN RESEARCH DEMONSTRATING THAT THE RESIDENT BACTERIA OF THE GASTROINTESTINAL TRACT, COLLECTIVELY THE GUT MICROBIOME, CAN HAVE TREMENDOUS INFLUENCE ON NEUROBIOLOGICAL AND BEHAVIORAL PLASTICITY. PREVIOUS WORK FROM OUR GROUP AND OTHERS HAS DEMONSTRATED THAT ALTERATIONS IN THE GUT MICROBIOME CAN ALTER BEHAVIORAL RESPONSES TO OPIOIDS IN MULTIPLE PARADIGMS. ADDITIONALLY, WE HAVE PREVIOUSLY REPORTED THAT DEPLETION OF THE GUT MICROBIOME WITH ANTIBIOTICS MARKEDLY SHIFTS THE TRANSCRIPTOME OF THE NUCLEUS ACCUMBENS FOLLOWING PROLONGED MORPHINE EXPOSURE. IN THIS MANUSCRIPT WE PRESENT A COMPREHENSIVE ANALYSIS OF THE EFFECTS OF THE GUT MICROBIOME ON TRANSCRIPTIONAL REGULATION OF THE NUCLEUS ACCUMBENS FOLLOWING MORPHINE BY UTILIZING GERM-FREE, ANTIBIOTIC TREATED, AND CONTROL MICE. THIS ALLOWS FOR DETAILED UNDERSTANDING OF THE ROLE OF THE MICROBIOME IN REGULATING BASELINE TRANSCRIPTOMIC CONTROL, AS WELL AS RESPONSE TO MORPHINE. WE FIND THAT GERM-FREE STATUS LEADS TO A MARKED GENE DYSREGULATION IN A MANNER DISTINCT TO ADULT MICE TREATED WITH ANTIBIOTICS, AND THAT ALTERED GENE PATHWAYS ARE HIGHLY RELATED TO CELLULAR METABOLIC PROCESSES. THESE DATA PROVIDE ADDITIONAL INSIGHT INTO THE ROLE OF THE GUT MICROBIOME IN MODULATING BRAIN FUNCTION AND LAY A FOUNDATION FOR FURTHER STUDY IN THIS AREA. 2023 9 2598 25 EPIGENETICS OF THE DEPRESSED BRAIN: ROLE OF HISTONE ACETYLATION AND METHYLATION. MAJOR DEPRESSIVE DISORDER IS A CHRONIC, REMITTING SYNDROME INVOLVING WIDELY DISTRIBUTED CIRCUITS IN THE BRAIN. STABLE ALTERATIONS IN GENE EXPRESSION THAT CONTRIBUTE TO STRUCTURAL AND FUNCTIONAL CHANGES IN MULTIPLE BRAIN REGIONS ARE IMPLICATED IN THE HETEROGENEITY AND PATHOGENESIS OF THE ILLNESS. EPIGENETIC EVENTS THAT ALTER CHROMATIN STRUCTURE TO REGULATE PROGRAMS OF GENE EXPRESSION HAVE BEEN ASSOCIATED WITH DEPRESSION-RELATED BEHAVIOR, ANTIDEPRESSANT ACTION, AND RESISTANCE TO DEPRESSION OR 'RESILIENCE' IN ANIMAL MODELS, WITH INCREASING EVIDENCE FOR SIMILAR MECHANISMS OCCURRING IN POSTMORTEM BRAINS OF DEPRESSED HUMANS. IN THIS REVIEW, WE DISCUSS RECENT ADVANCES IN OUR UNDERSTANDING OF EPIGENETIC CONTRIBUTIONS TO DEPRESSION, IN PARTICULAR THE ROLE OF HISTONE ACETYLATION AND METHYLATION, WHICH ARE REVEALING NOVEL MECHANISTIC INSIGHT INTO THE SYNDROME THAT MAY AID IN THE DEVELOPMENT OF NOVEL TARGETS FOR DEPRESSION TREATMENT. 2013 10 5645 35 SEX DEPENDENT ALTERATION OF EPIGENETIC MARKS AFTER CHRONIC MORPHINE TREATMENT IN MICE ORGANS. EPIGENETIC MARKS MAY BE ALSO AFFECTED BY SEVERAL FACTORS, SUCH AS AGE, LIFESTYLE, EARLY LIFE EXPERIENCES AND EXPOSURE TO CHEMICALS OR DRUGS, SUCH AS OPIOIDS. PREVIOUS STUDIES HAVE FOCUSED ON HOW MORPHINE EPIGENETICALLY REGULATES DIFFERENT REGIONS OF THE BRAIN THAT ARE IMPLICATED IN TOLERANCE, DEPENDENCE AND OTHER PSYCHIATRIC DISORDERS MORE RELATED TO THE PHYSIO-PATHOLOGICAL EFFECTS OF OPIOIDS. NEVERTHELESS, A SIGNIFICANT KNOWLEDGE GAP REMAINS REGARDING THE EFFECT OF CHRONIC TREATMENT ON OTHER ORGANS AND BIOLOGICAL SYSTEMS. THEREFORE, THE AIM OF THIS WORK IS TO INCREASE OUR KNOWLEDGE ABOUT THE IMPACT OF CHRONIC MORPHINE EXPOSURE ON DNA METHYLATION AND HISTONE MODIFICATION LEVELS IN EACH OF THE ORGANS OF MALE AND FEMALE MODEL MICE IN VIVO. OUR RESULTS REVEAL, FOR THE FIRST TIME, THAT CHRONIC MORPHINE TREATMENT INDUCED CHANGES IN DNA METHYLATION/HYDROXYMETHYLATION AND HISTONE MODIFICATION IN-VIVO AT THE SYSTEMIC LEVEL, REVEALING A POTENTIAL PHYSIOLOGICAL EFFECT ON THE REGULATION OF GENE EXPRESSION. NOTABLY, MORPHINE-INDUCED EPIGENETIC MODIFICATION OCCURS IN A SEX-DEPENDENT MANNER, REVEALING THE EXISTENCE OF DIFFERENT UNDERLYING MECHANISMS OF EPIGENETIC MODIFICATION IN MALE AND FEMALE MICE. 2021 11 5649 24 SEX DIFFERENCES IN PSYCHOSTIMULANT ABUSE: IMPLICATIONS FOR ESTROGEN RECEPTORS AND HISTONE DEACETYLASES. SUBSTANCE ABUSE IS A CHRONIC PATHOLOGICAL DISORDER THAT NEGATIVELY AFFECTS MANY HEALTH AND NEUROLOGICAL PROCESSES. A GROWING BODY OF LITERATURE HAS REVEALED GENDER DIFFERENCES IN SUBSTANCE USE. COMPARED TO MEN, WOMEN DISPLAY DISTINCT DRUG-USE PHENOTYPES ACCOMPANIED BY RECOVERY AND REHABILITATION DISPARITIES. THESE OBSERVATIONS HAVE LED TO THE NOTION THAT SEX-DEPENDENT SUSCEPTIBILITIES EXIST ALONG THE PROGRESSION TO ADDICTION. WITHIN THIS SCOPE, NEUROADAPTATIONS FOLLOWING PSYCHOSTIMULANT EXPOSURE ARE THOUGHT TO BE DISTINCT FOR EACH SEX. THIS REVIEW SUMMARIZES CLINICAL FINDINGS AND ANIMAL RESEARCH REPORTING SEX DIFFERENCES IN THE SUBJECTIVE AND BEHAVIORAL RESPONSES TO COCAINE, METHAMPHETAMINE, AND NICOTINE. THIS DISCUSSION IS FOLLOWED BY AN EXAMINATION OF EPIGENETIC AND MOLECULAR ALTERATIONS IMPLICATED IN THE ADDICTION PROCESS. SPECIAL CONSIDERATION IS GIVEN TO HISTONE DEACETYLASES AND ESTROGEN RECEPTOR-MEDIATED GENE EXPRESSION. 2022 12 5067 34 PHYSICAL ACTIVITY AND DNA METHYLATION IN HUMANS. PHYSICAL ACTIVITY IS A STRONG STIMULUS INFLUENCING THE OVERALL PHYSIOLOGY OF THE HUMAN BODY. EXERCISES LEAD TO BIOCHEMICAL CHANGES IN VARIOUS TISSUES AND EXERT AN IMPACT ON GENE EXPRESSION. EXERCISE-INDUCED CHANGES IN GENE EXPRESSION MAY BE MEDIATED BY EPIGENETIC MODIFICATIONS, WHICH REARRANGE THE CHROMATIN STRUCTURE AND THEREFORE MODULATE ITS ACCESSIBILITY FOR TRANSCRIPTION FACTORS. ONE OF SUCH EPIGENETIC MARK IS DNA METHYLATION THAT INVOLVES AN ATTACHMENT OF A METHYL GROUP TO THE FIFTH CARBON OF CYTOSINE RESIDUE PRESENT IN CG DINUCLEOTIDES (CPG). DNA METHYLATION IS CATALYZED BY A FAMILY OF DNA METHYLTRANSFERASES. THIS REVERSIBLE DNA MODIFICATION RESULTS IN THE RECRUITMENT OF PROTEINS CONTAINING METHYL BINDING DOMAIN AND FURTHER TRANSCRIPTIONAL CO-REPRESSORS LEADING TO THE SILENCING OF GENE EXPRESSION. THE ACCUMULATION OF CPG DINUCLEOTIDES, REFERRED AS CPG ISLANDS, OCCURS AT THE PROMOTER REGIONS IN A GREAT MAJORITY OF HUMAN GENES. THEREFORE, CHANGES IN DNA METHYLATION PROFILE AFFECT THE TRANSCRIPTION OF MULTIPLE GENES. A GROWING BODY OF EVIDENCE INDICATES THAT EXERCISE TRAINING MODULATES DNA METHYLATION IN MUSCLES AND ADIPOSE TISSUE. SOME OF THESE EPIGENETIC MARKERS WERE ASSOCIATED WITH A REDUCED RISK OF CHRONIC DISEASES. THIS REVIEW SUMMARIZES THE CURRENT KNOWLEDGE ABOUT THE INFLUENCE OF PHYSICAL ACTIVITY ON THE DNA METHYLATION STATUS IN HUMANS. 2021 13 2523 35 EPIGENETICS AND THE TRANSITION FROM ACUTE TO CHRONIC PAIN. OBJECTIVE: THE OBJECTIVE OF THIS STUDY WAS TO REVIEW THE EPIGENETIC MODIFICATIONS INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN AND TO IDENTIFY POTENTIAL TARGETS FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED PAIN THERAPEUTICS. BACKGROUND: EPIGENETICS IS THE STUDY OF HERITABLE MODIFICATIONS IN GENE EXPRESSION AND PHENOTYPE THAT DO NOT REQUIRE A CHANGE IN GENETIC SEQUENCE TO MANIFEST THEIR EFFECTS. ENVIRONMENTAL TOXINS, MEDICATIONS, DIET, AND PSYCHOLOGICAL STRESSES CAN ALTER EPIGENETIC PROCESSES SUCH AS DNA METHYLATION, HISTONE ACETYLATION, AND RNA INTERFERENCE. AS EPIGENETIC MODIFICATIONS POTENTIALLY PLAY AN IMPORTANT ROLE IN INFLAMMATORY CYTOKINE METABOLISM, STEROID RESPONSIVENESS, AND OPIOID SENSITIVITY, THEY ARE LIKELY KEY FACTORS IN THE DEVELOPMENT OF CHRONIC PAIN. ALTHOUGH OUR KNOWLEDGE OF THE HUMAN GENETIC CODE AND DISEASE-ASSOCIATED POLYMORPHISMS HAS GROWN SIGNIFICANTLY IN THE PAST DECADE, WE HAVE NOT YET BEEN ABLE TO ELUCIDATE THE MECHANISMS THAT LEAD TO THE DEVELOPMENT OF PERSISTENT PAIN AFTER NERVE INJURY OR SURGERY. DESIGN: THIS IS A FOCUSED LITERATURE REVIEW OF EPIGENETIC SCIENCE AND ITS RELATIONSHIP TO CHRONIC PAIN. RESULTS: SIGNIFICANT LABORATORY AND CLINICAL DATA SUPPORT THE NOTION THAT EPIGENETIC MODIFICATIONS ARE AFFECTED BY THE ENVIRONMENT AND LEAD TO DIFFERENTIAL GENE EXPRESSION. SIMILAR TO MECHANISMS INVOLVED IN THE DEVELOPMENT OF CANCER, NEURODEGENERATIVE DISEASE, AND INFLAMMATORY DISORDERS, THE LITERATURE ENDORSES AN IMPORTANT POTENTIAL ROLE FOR EPIGENETICS IN CHRONIC PAIN. CONCLUSIONS: EPIGENETIC ANALYSIS MAY IDENTIFY MECHANISMS CRITICAL TO THE DEVELOPMENT OF CHRONIC PAIN AFTER INJURY, AND MAY PROVIDE NEW PATHWAYS AND TARGET MECHANISMS FOR FUTURE DRUG DEVELOPMENT AND INDIVIDUALIZED MEDICINE. 2012 14 2235 23 EPIGENETIC MODIFICATIONS, ALCOHOLIC BRAIN AND POTENTIAL DRUG TARGETS. ACUTE AND CHRONIC ALCOHOL EXPOSURE EVIDENTLY INFLUENCES EPIGENETIC CHANGES, BOTH TRANSIENTLY AND PERMANENTLY, AND THESE CHANGES IN TURN INFLUENCE A VARIETY OF CELLS AND ORGAN SYSTEMS THROUGHOUT THE BODY. MANY OF THE ALCOHOL-INDUCED EPIGENETIC MODIFICATIONS CAN CONTRIBUTE TO CELLULAR ADAPTATIONS THAT ULTIMATELY LEAD TO BEHAVIORAL TOLERANCE AND ALCOHOL DEPENDENCE. THE PERSISTENCE OF BEHAVIORAL CHANGES DEMONSTRATES THAT LONG-LASTING CHANGES IN GENE EXPRESSION, WITHIN PARTICULAR REGIONS OF THE BRAIN, MAY CONTRIBUTE IMPORTANTLY TO THE ADDICTION PHENOTYPE. THE RESEARCH ACTIVITIES OVER THE PAST YEARS HAVE DEMONSTRATED A CRUCIAL ROLE OF EPIGENETIC MECHANISMS IN CAUSING LONG LASTING AND TRANSIENT CHANGES IN THE EXPRESSION OF SEVERAL GENES IN DIVERSE TISSUES, INCLUDING BRAIN. THIS HAS STIMULATED RECENT RESEARCH WORK THAT IS AIMED AT CHARACTERIZING THE INFLUENCE OF EPIGENETIC REGULATORY EVENTS IN MEDIATING THE LONG LASTING AND TRANSIENT EFFECTS OF ALCOHOL ABUSE ON THE BRAIN IN HUMANS AND ANIMAL MODELS OF ALCOHOL ADDICTION. IN THIS STUDY, WE UPDATE OUR CURRENT UNDERSTANDING OF THE IMPACT OF ALCOHOL EXPOSURE ON EPIGENETIC MECHANISMS IN THE BRAIN AND REFURBISH THE KNOWLEDGE OF EPIGENETICS IN THE DIRECTION OF NEW DRUGS DEVELOPMENT. 2016 15 2913 29 GENE REGULATORY MECHANISMS UNDERLYING SEX DIFFERENCES IN BRAIN DEVELOPMENT AND PSYCHIATRIC DISEASE. THE SEXUAL DIFFERENTIATION OF THE MAMMALIAN NERVOUS SYSTEM REQUIRES THE PRECISE COORDINATION OF THE TEMPORAL AND SPATIAL REGULATION OF GENE EXPRESSION IN DIVERSE CELL TYPES. SEX HORMONES ACT AT MULTIPLE DEVELOPMENTAL TIME POINTS TO SPECIFY SEX-TYPICAL DIFFERENTIATION DURING EMBRYONIC AND EARLY DEVELOPMENT AND TO COORDINATE SUBSEQUENT RESPONSES TO GONADAL HORMONES LATER IN LIFE BY ESTABLISHING SEX-TYPICAL PATTERNS OF EPIGENETIC MODIFICATIONS ACROSS THE GENOME. THUS, MUTATIONS ASSOCIATED WITH NEUROPSYCHIATRIC CONDITIONS MAY RESULT IN SEXUALLY DIMORPHIC SYMPTOMS BY ACTING ON DIFFERENT NEURAL SUBSTRATES OR CHROMATIN LANDSCAPES IN MALES AND FEMALES. FINALLY, AS STRESS HORMONE SIGNALING MAY DIRECTLY ALTER THE MOLECULAR MACHINERY THAT INTERACTS WITH SEX HORMONE RECEPTORS TO REGULATE GENE EXPRESSION, THE CONTRIBUTION OF CHRONIC STRESS TO THE PATHOGENESIS OR PRESENTATION OF MENTAL ILLNESS MAY BE ADDITIONALLY DIFFERENT BETWEEN THE SEXES. HERE, WE REVIEW THE MECHANISMS THAT CONTRIBUTE TO SEXUAL DIFFERENTIATION IN THE MAMMALIAN NERVOUS SYSTEM AND CONSIDER SOME OF THE IMPLICATIONS OF THESE PROCESSES FOR SEX DIFFERENCES IN NEUROPSYCHIATRIC CONDITIONS. 2018 16 6895 21 [SYSTEMIC CONTROL OF THE MOLECULAR, CELL, AND EPIGENETIC MECHANISMS OF LONG-LASTING CONSEQUENCES OF STRESS]. BASED ON M.E. LOBASHEV'S VIEWS OF THE SYSTEMIC CONTROL OF GENETIC AND CYTOGENEITC PROCESSES AND A SUBSTANTIAL EFFECT OF EXCITABILITY ON PLASTIC CHANGES IN THE CENTRAL NERVOUS SYSTEM (CNS), THE EFFECT OF PROLONGED EMOTIONAL AND PAIN STRESS (PEPS) ON THE MOLECULAR, CELL, AND EPIGENETIC MECHANISMS OF INJURY MEMORY WAS STUDIED IN RAT STRAINS BRED FOR A CERTAIN EXCITABILITY OF THE NERVOUS SYSTEM. PEPS WAS FOR THE FIRST TIME FOUND TO CAUSE LONG-LASTING (2 MONTHS) MORPHOLOGICAL ALTERATIONS OF THE CA3 REGION OF THE HIPPOCAMPUS AND TO MODIFY THE GENOME ACTIVITY OF ITS PYRAMIDAL NEURONS. THE TWO PHENOMENA WERE POTENTIATED BY A GENETICALLY DETERMINED LOW FUNCTIONAL STATE OF THE CNS. THE POST-STRESS REGULATION OF THE GENOME FUNCTION IN HIPPOCAMPAL NEURONS WAS MEDIATED BY CHANGES IN HETEROCHROMATIN CONFORMATION, ACTIVATION OF METHYL-CPG-BINDING PROTEIN (MECP2) SYNTHESIS, AND SUBSEQUENT CHANGES IN ACETYLATION OF HISTONE H4. GENETICALLY DETERMINED HIGH EXCITABILITY OF THE NERVOUS SYSTEM PROVED TO BE A RISK FACTOR THAT AFFECTS THE SPECIFICS AND TIME COURSE OF THE OBSERVED MOLECULAR, CELL, AND GENETIC TRANSFORMATIONS OF NEURONS. THE RESULTS PROVIDE FOR A BETTER UNDERSTANDING OF THE EPIGENETIC MECHANISMS OF INJURY MEMORY, WHICH FORMS A PATHOGENETIC BASIS FOR POSTTRAUMATIC STRESS DISORDER AND OTHER HUMAN PSYCHOGENIC CONDITIONS CHARACTERIZED BY A PROLONGED DURATION. 2009 17 834 32 CHEMICAL BIOLOGY OF LYSINE DEMETHYLASES. ABNORMAL LEVELS OF DNA METHYLATION AND/OR HISTONE MODIFICATIONS ARE OBSERVED IN PATIENTS WITH A WIDE VARIETY OF CHRONIC DISEASES. METHYLATION OF LYSINES WITHIN HISTONE TAILS IS A KEY MODIFICATION THAT CONTRIBUTES TO INCREASED GENE EXPRESSION OR REPRESSION DEPENDING ON THE SPECIFIC RESIDUE AND DEGREE OF METHYLATION, WHICH IS IN TURN CONTROLLED BY THE INTERPLAY OF LYSINE METHYL TRANSFERASES AND DEMETHYLASES. DRUGS THAT TARGET THESE AND OTHER ENZYMES CONTROLLING CHROMATIN MODIFICATIONS CAN MODULATE THE EXPRESSION OF CLUSTERS OF GENES, POTENTIALLY OFFERING HIGHER THERAPEUTIC EFFICACY THAN CLASSICAL AGENTS ACTING ON DOWNSTREAM BIOCHEMICAL PATHWAYS THAT ARE SUSCEPTIBLE TO DEGENERACY. LYSINE DEMETHYLASES, FIRST DISCOVERED IN 2004, ARE THE SUBJECT OF INCREASING INTEREST AS THERAPEUTIC TARGETS. THIS REVIEW PROVIDES AN OVERVIEW OF RECENT FINDINGS IMPLICATING LYSINE DEMETHYLASES IN A RANGE OF THERAPEUTIC AREAS INCLUDING ONCOLOGY, IMMUNOINFLAMMATION, METABOLIC DISORDERS, NEUROSCIENCE, VIROLOGY AND REGENERATIVE MEDICINE, TOGETHER WITH A SUMMARY OF RECENT ADVANCES IN STRUCTURAL BIOLOGY AND SMALL MOLECULE INHIBITOR DISCOVERY, SUPPORTING THE TRACTABILITY OF THE PROTEIN FAMILY FOR THE DEVELOPMENT OF SELECTIVE DRUGLIKE INHIBITORS. 2011 18 2412 46 EPIGENETIC SIDE-EFFECTS OF COMMON PHARMACEUTICALS: A POTENTIAL NEW FIELD IN MEDICINE AND PHARMACOLOGY. THE TERM "EPIGENETICS" REFERS TO DNA AND CHROMATIN MODIFICATIONS THAT PERSIST FROM ONE CELL DIVISION TO THE NEXT, DESPITE A LACK OF CHANGE IN THE UNDERLYING DNA SEQUENCE. THE "EPIGENOME" REFERS TO THE OVERALL EPIGENETIC STATE OF A CELL, AND SERVES AS AN INTERFACE BETWEEN THE ENVIRONMENT AND THE GENOME. THE EPIGENOME IS DYNAMIC AND RESPONSIVE TO ENVIRONMENTAL SIGNALS NOT ONLY DURING DEVELOPMENT, BUT ALSO THROUGHOUT LIFE; AND IT IS BECOMING INCREASINGLY APPARENT THAT CHEMICALS CAN CAUSE CHANGES IN GENE EXPRESSION THAT PERSIST LONG AFTER EXPOSURE HAS CEASED. HERE WE PRESENT THE HYPOTHESIS THAT COMMONLY-USED PHARMACEUTICAL DRUGS CAN CAUSE SUCH PERSISTENT EPIGENETIC CHANGES. DRUGS MAY ALTER EPIGENETIC HOMEOSTASIS BY DIRECT OR INDIRECT MECHANISMS. DIRECT EFFECTS MAY BE CAUSED BY DRUGS WHICH AFFECT CHROMATIN ARCHITECTURE OR DNA METHYLATION. FOR EXAMPLE THE ANTIHYPERTENSIVE HYDRALAZINE INHIBITS DNA METHYLATION. AN EXAMPLE OF AN INDIRECTLY ACTING DRUG IS ISOTRETINOIN, WHICH HAS TRANSCRIPTION FACTOR ACTIVITY. A TWO-TIER MECHANISM IS POSTULATED FOR INDIRECT EFFECTS IN WHICH ACUTE EXPOSURE TO A DRUG INFLUENCES SIGNALING PATHWAYS THAT MAY LEAD TO AN ALTERATION OF TRANSCRIPTION FACTOR ACTIVITY AT GENE PROMOTERS. THIS STIMULATION RESULTS IN THE ALTERED EXPRESSION OF RECEPTORS, SIGNALING MOLECULES, AND OTHER PROTEINS NECESSARY TO ALTER GENETIC REGULATORY CIRCUITS. WITH MORE CHRONIC EXPOSURE, CELLS ADAPT BY AN UNKNOWN HYPOTHETICAL PROCESS THAT RESULTS IN MORE PERMANENT MODIFICATIONS TO DNA METHYLATION AND CHROMATIN STRUCTURE, LEADING TO ENDURING ALTERATION OF A GIVEN EPIGENETIC NETWORK. THEREFORE, ANY EPIGENETIC SIDE-EFFECT CAUSED BY A DRUG MAY PERSIST AFTER THE DRUG IS DISCONTINUED. IT IS FURTHER PROPOSED THAT SOME IATROGENIC DISEASES SUCH AS TARDIVE DYSKINESIA AND DRUG-INDUCED SLE ARE EPIGENETIC IN NATURE. IF THIS HYPOTHESIS IS CORRECT THE CONSEQUENCES FOR MODERN MEDICINE ARE PROFOUND, SINCE IT WOULD IMPLY THAT OUR CURRENT UNDERSTANDING OF PHARMACOLOGY IS AN OVERSIMPLIFICATION. WE PROPOSE THAT EPIGENETIC SIDE-EFFECTS OF PHARMACEUTICALS MAY BE INVOLVED IN THE ETIOLOGY OF HEART DISEASE, CANCER, NEUROLOGICAL AND COGNITIVE DISORDERS, OBESITY, DIABETES, INFERTILITY, AND SEXUAL DYSFUNCTION. IT IS SUGGESTED THAT A SYSTEMS BIOLOGY APPROACH EMPLOYING MICROARRAY ANALYSES OF GENE EXPRESSION AND METHYLATION PATTERNS CAN LEAD TO A BETTER UNDERSTANDING OF LONG-TERM SIDE-EFFECTS OF DRUGS, AND THAT IN THE FUTURE, EPIGENETIC ASSAYS SHOULD BE INCORPORATED INTO THE SAFETY ASSESSMENT OF ALL PHARMACEUTICAL DRUGS. THIS NEW APPROACH TO PHARMACOLOGY HAS BEEN TERMED "PHAMACOEPIGENOMICS", THE IMPACT OF WHICH MAY BE EQUAL TO OR GREATER THAN THAT OF PHARMACOGENETICS. WE PROVIDE HERE AN OVERVIEW OF THIS POTENTIALLY MAJOR NEW FIELD IN PHARMACOLOGY AND MEDICINE. 2009 19 6771 30 [ACQUIRED DISORDERS AND EPIGENETICS]. EPIGENETIC MODIFICATIONS, INVOLVING DNA METHYLATION AND HISTONE MODIFICATIONS, ARE MAINTAINED UPON SOMATIC CELL REPLICATION, AND ARE FUNDAMENTAL MECHANISMS FOR CELLULAR MEMORY. DNA METHYLATION OF PROMOTER CPG ISLANDS OF TUMOR-SUPPRESSOR GENES CAN SILENCE THEIR DOWNSTREAM GENES, AND CAN BE CAUSALLY INVOLVED IN CANCER DEVELOPMENT AND PROGRESSION. SINCE THIS EFFECT IS THE SAME WITH THAT OF INACTIVATING MUTATIONS, THE NATURES OF DNA METHYLATION WERE ONCE CONSIDERED TO BE SIMILAR TO MUTATIONS. HOWEVER, RECENTLY, IT WAS REVEALED THAT A LARGE NUMBER OF EPIGENETIC ALTERATIONS ARE PRESENT IN A SINGLE CANCER CELL, THAT A LARGE NUMBER OF CELLS HAVE AN EPIGENETIC ALTERATION OF A SPECIFIC GENE IN NON-CANCEROUS, THUS POLYCLONAL, TISSUES, THAT GENE SPECIFICITY IN METHYLATION INDUCTION IS PRESENT ACCORDING TO TISSUE TYPES AND INDUCERS, AND THAT CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN METHYLATION INDUCTION. THESE FACTS SUGGEST THAT EPIGENETIC ALTERATIONS OF KEY GENES INVOLVED IN ACQUIRED CHRONIC DISORDERS CAN BE PRESENT IN A SIGNIFICANT FRACTION OF CELLS IN A TISSUE, AND THUS CAN IMPAIR THE FUNCTION OF THE TISSUE. ASSOCIATIONS BETWEEN EPIGENETIC ALTERATIONS AND BEHAVIOR, MEMORY, MENTAL DISORDERS, NEUROLOGICAL DISORDERS, METABOLIC DISORDERS, ALLERGY, AUTOIMMUNE DISORDERS, AND OTHER DISORDERS HAVE BEEN REPORTED. FURTHER RESEARCH IN THE FIELD IS NECESSARY TO CLARIFY THE CAUSAL ROLES OF THESE EPIGENETIC ALTERATIONS IN DISEASE DEVELOPMENT, AND TO APPLY THE FINDINGS TO NEW STRATEGIES OF DISEASE PREVENTION, DIAGNOSIS, AND TREATMENT. 2010 20 6199 34 THE IMPORTANCE OF EPIGENETICS IN THE DEVELOPMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. IT IS GENERALLY ACCEPTED THAT GENETIC PREDISPOSITION PLAYS A ROLE IN COPD DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS. THEREFORE, MANY CANDIDATE GENES THAT COULD BE LINKED TO THE DEVELOPMENT OF DISEASE HAVE BEEN EXAMINED IN COPD. HOWEVER, INCONSISTENT RESULTS IN DIFFERENT STUDY POPULATIONS OFTEN LIMIT THIS APPROACH, SUGGESTING THAT NOT ONLY GENETICS, BUT ALSO OTHER FACTORS, MAY BE CONTRIBUTED TO THE SUSCEPTIBILITY TO COPD. EPIGENETIC MECHANISMS CAN AFFECT THE TRANSCRIPTIONAL ACTIVITY OF SPECIFIC GENES, AT DIFFERENT POINTS IN TIME, AND IN DIFFERENT ORGANS. MOREOVER, THESE MECHANISMS CAN HAVE AN EFFECT ON PEOPLE'S HEALTH. RECENTLY, THERE IS EMERGING EVIDENCE SUPPORTING A ROLE OF EPIGENETICS FOR THE REGULATION OF INFLAMMATORY GENES IN DISEASES SUCH AS ASTHMA AND COPD. MOREOVER, RECENT STUDIES SUGGEST THAT THE CURRENTLY USED TREATMENTS INCLUDING CORTICOSTEROIDS MAY WORK THROUGH EPIGENETIC MECHANISMS. EPIGENETIC REGULATION CAN BE REPROGRAMMED, POTENTIALLY AFFECTING THE RISK, AETIOLOGY AND TREATMENT OF VARIOUS DISEASE STATES. THE EPIGENETICALLY INFLUENCED PHENOTYPE COULD BE REVERSED WITH DEMETHYLATING OR DEACETYLATING AGENTS, CONSISTENT WITH EPIGENETIC PLASTICITY. THE POSTNATAL REVERSIBILITY OF THESE METHYLATION OR ACETYLATION EVENTS MAY THEREFORE PROVIDE GOOD OPPORTUNITIES FOR INTERVENTION. THE RECOGNITION OF THE ROLE OF GENETIC AND EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF COPD MAY IDENTIFY NOVEL TARGETS THAT HATCH NEW THERAPIES FOR PATIENTS WITH COPD. 2011