1 5515 122 RILUZOLE ADMINISTRATION TO RATS WITH LEVODOPA-INDUCED DYSKINESIA LEADS TO LOSS OF DNA METHYLATION IN NEURONAL GENES. DYSKINESIAS ARE CHARACTERIZED BY ABNORMAL REPETITIVE INVOLUNTARY MOVEMENTS DUE TO DYSFUNCTIONAL NEURONAL ACTIVITY. ALTHOUGH LEVODOPA-INDUCED DYSKINESIA, CHARACTERIZED BY TIC-LIKE ABNORMAL INVOLUNTARY MOVEMENTS, HAS NO CLINICAL TREATMENT FOR PARKINSON'S DISEASE PATIENTS, ANIMAL STUDIES INDICATE THAT RILUZOLE, WHICH INTERFERES WITH GLUTAMATERGIC NEUROTRANSMISSION, CAN IMPROVE THE PHENOTYPE. THE RAT MODEL OF LEVODOPA-INDUCED DYSKINESIA IS A UNILATERAL LESION WITH 6-HYDROXYDOPAMINE IN THE MEDIAL FOREBRAIN BUNDLE, FOLLOWED BY THE REPEATED ADMINISTRATION OF LEVODOPA. THE MOLECULAR PATHOMECHANISM OF LEVODOPA-INDUCED DYSKINESIA IS STILL NOT DECIPHERED; HOWEVER, THE IMPLICATION OF EPIGENETIC MECHANISMS WAS SUGGESTED. IN THIS STUDY, WE INVESTIGATED THE STRIATUM FOR DNA METHYLATION ALTERATIONS UNDER CHRONIC LEVODOPA TREATMENT WITH OR WITHOUT CO-TREATMENT WITH RILUZOLE. OUR DATA SHOW THAT THE LESIONED AND CONTRALATERAL STRIATA HAVE NEARLY IDENTICAL DNA METHYLATION PROFILES. CHRONIC LEVODOPA AND LEVODOPA + RILUZOLE TREATMENTS LED TO DNA METHYLATION LOSS, PARTICULARLY OUTSIDE OF PROMOTERS, IN GENE BODIES AND CPG POOR REGIONS. WE OBSERVED THAT SEVERAL GENES INVOLVED IN THE LEVODOPA-INDUCED DYSKINESIA UNDERWENT METHYLATION CHANGES. FURTHERMORE, THE RILUZOLE CO-TREATMENT, WHICH IMPROVED THE PHENOTYPE, PINPOINTED SPECIFIC METHYLATION TARGETS, WITH A MORE THAN 20% METHYLATION DIFFERENCE RELATIVE TO LEVODOPA TREATMENT ALONE. THESE FINDINGS INDICATE POTENTIAL NEW DRUGGABLE TARGETS FOR LEVODOPA-INDUCED DYSKINESIA. 2021 2 6432 30 THE VICIOUS CIRCLE BETWEEN HOMOCYSTEINE, METHYL GROUP-DONATING VITAMINS AND CHRONIC LEVODOPA INTAKE IN PARKINSON'S DISEASE. A BIOMARKER FOR DECLINED METHYLATION CAPACITY IS ELEVATION OF HOMOCYSTEINE LEVELS. THEY INCREASE THE RISK FOR ONSET OF VASCULAR DISEASE AND CONTRIBUTE TO PROGRESSION OF CHRONIC NEURODEGENERATION AND AGING. THIS NARRATIVE REVIEW DISCUSSES ASSOCIATIONS BETWEEN HOMOCYSTEINE, CONSUMPTION OF METHYL GROUP-DONATING VITAMINS AND IMPACT ON DISEASE-GENERATING MECHANISMS IN LEVODOPA-TREATED PATIENTS WITH PARKINSON'S DISEASE. WE CONCLUDE TO RECOMMEND LEVODOPA-TREATED PATIENTS TO SUBSTITUTE THEMSELVES WITH METHYL GROUP-DONATING VITAMINS. THIS IS HARMLESS IN TERMS OF APPLICATION OF FOLIC ACID, METHYLCOBALAMIN OR HYDROXOCOBALAMIN. MOREOVER, WE SUGGEST A CRUCIAL DISCUSSION ON THE VALUE OF THE VARIOUS POPULAR HYPOTHESES ON PARKINSON'S DISEASE-GENERATING MECHANISMS. FINDINGS FROM STUDIES WITH ACUTE LEVODOPA EXPOSURE DESCRIBE OXIDATIVE STRESS GENERATION AND IMPAIRED METHYLATION CAPACITY, WHICH CAUSES GENE DYSFUNCTION. THEIR REPEATED OCCURRENCES CONTRIBUTE TO ONSET OF MITOCHONDRIAL DYSFUNCTION, IRON ENRICHMENT AND PATHOLOGIC PROTEIN ACCUMULATION IN THE LONG TERM. CURRENT RESEARCH UNDERESTIMATES THESE EPIGENETIC, METABOLIC CONSEQUENCES OF CHRONIC LEVODOPA APPLICATION. SUPPLEMENTARY TREATMENT STRATEGIES ARE RECOMMENDED TO AVOID LEVODOPA-RELATED SIDE EFFECTS. 2023 3 6775 36 [ALCOHOL DEPENDENCE MEDIATED BY MONOAMINE NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM]. ALCOHOL DEPENDENCE, A CHRONIC RELAPSING BRAIN DISEASE WITH THE CHARACTERISTICS OF DRINKING ALCOHOL OUT OF CONTROL, HAS BECOME A SERIOUS SOCIAL PROBLEM. MONOAMINE NEUROTRANSMITTERS, MAINLY INCLUDING DOPAMINE AND 5-HYDROXYTRYP NOTTAMINE, PLAY IMPORTANT ROLES IN THE OCCURRENCE, DEVELOPMENT AND NEURAL DYSFUNCTION OF ALCOHOL DEPENDENCE SYNDROME. IN THIS REVIEW, THE ROLES OF KEY FACTORS OF THE MONOAMINE SYSTEM (DOPAMINE RECEPTOR GENES, 5-HYDROXYTRYPTAMINE RECEPTOR GENES, TRANSPORTER GENES, TYROSINE HYDROXYLASE GENE, TRYPTOPHANHYDROXYLASE GENE AND MONOAMINE OXIDASE GENE) IN ALCOHOL DEPENDENCE WERE DISCUSSED, AND STRATEGIES FOR FURTHER STUDIES OF MOLECULAR MECHANISMS WERE PROPOSED BASED ON GENE KNOCKOUT MICE MODELS GENERATED IN OUR LABORATORY. THEN, COMBINING WITH STUDIES ON TYROSINE HYDROXYLASE ACTIVATOR CAMKII IN OUR LAB, THERAPEUTIC TARGETS WERE DISCUSSED. BESIDES, EPIGENETIC STRATEGIES FOR PREVENTION AND TREATMENT OF ALCOHOL DEPENDENCE SYNDROME WERE PROPOSED. FURTHERMORE, MANIPULATING METHYLATION LEVELS IN GENE REGULATORY REGIONS AND ALTERNATIVE SPLICING OF PRE-MRNAS MIGHT ALSO HAVE CLINICAL IMPLICATIONS. FINALLY, BASED ON NEW FINDINGS ON GENETIC POLYMORPHISM, IT IS OF GREAT POTENTIAL TO CARRY OUT INDIVIDUAL PREVENTION AND TREATMENT FOR PATIENTS SUFFERING FROM ALCOHOL DEPENDENCE. 2014 4 2119 28 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 2350 32 EPIGENETIC REGULATION OF NEUROINFLAMMATION IN PARKINSON'S DISEASE. NEUROINFLAMMATION IS ONE OF THE MOST SIGNIFICANT FACTORS INVOLVED IN THE INITIATION AND PROGRESSION OF PARKINSON'S DISEASE. PD IS A NEURODEGENERATIVE DISORDER WITH A MOTOR DISABILITY LINKED WITH VARIOUS COMPLEX AND DIVERSIFIED RISK FACTORS. THESE FACTORS TRIGGER MYRIADS OF CELLULAR AND MOLECULAR PROCESSES, SUCH AS MISFOLDING DEFECTIVE PROTEINS, OXIDATIVE STRESS, MITOCHONDRIAL DYSFUNCTION, AND NEUROTOXIC SUBSTANCES THAT INDUCE SELECTIVE NEURODEGENERATION OF DOPAMINE NEURONS. THIS NEURONAL DAMAGE ACTIVATES THE NEURONAL IMMUNE SYSTEM, INCLUDING GLIAL CELLS AND INFLAMMATORY CYTOKINES, TO TRIGGER NEUROINFLAMMATION. THE TRANSITION OF ACUTE TO CHRONIC NEUROINFLAMMATION ENHANCES THE SUSCEPTIBILITY OF INFLAMMATION-INDUCED DOPAMINERGIC NEURON DAMAGE, FORMING A VICIOUS CYCLE AND PROMPTING AN INDIVIDUAL TO PD DEVELOPMENT. EPIGENETIC MECHANISMS RECENTLY HAVE BEEN AT THE FOREFRONT OF THE REGULATION OF NEUROINFLAMMATORY FACTORS IN PD, PROPOSING A NEW DAWN FOR BREAKING THIS VICIOUS CYCLE. THIS REVIEW EXAMINED THE CORE EPIGENETIC MECHANISMS INVOLVED IN THE ACTIVATION AND PHENOTYPIC TRANSFORMATION OF GLIAL CELLS MEDIATED NEUROINFLAMMATION IN PD. WE FOUND THAT EPIGENETIC MECHANISMS DO NOT WORK INDEPENDENTLY, DESPITE BEING COORDINATED WITH EACH OTHER TO ACTIVATE NEUROINFLAMMATORY PATHWAYS. IN THIS REGARD, WE ATTEMPTED TO FIND THE SYNERGIC CORRELATION AND CONTRIBUTION OF THESE EPIGENETIC MODIFICATIONS WITH VARIOUS NEUROINFLAMMATORY PATHWAYS TO BROADEN THE CANVAS OF UNDERLYING PATHOLOGICAL MECHANISMS INVOLVED IN PD DEVELOPMENT. MOREOVER, THIS STUDY HIGHLIGHTED THE DUAL CHARACTERISTICS (NEUROPROTECTIVE/NEUROTOXIC) OF THESE EPIGENETIC MARKS, WHICH MAY COUNTERACT PD PATHOGENESIS AND MAKE THEM POTENTIAL CANDIDATES FOR DEVISING FUTURE PD DIAGNOSIS AND TREATMENT. 2021 6 3137 35 GLOBAL DNA METHYLATION PROFILING OF MANGANESE-EXPOSED HUMAN NEUROBLASTOMA SH-SY5Y CELLS REVEALS EPIGENETIC ALTERATIONS IN PARKINSON'S DISEASE-ASSOCIATED GENES. MANGANESE (MN) IS AN ESSENTIAL TRACE ELEMENT REQUIRED FOR OPTIMAL FUNCTIONING OF CELLULAR BIOCHEMICAL PATHWAYS IN THE CENTRAL NERVOUS SYSTEM. ELEVATED EXPOSURE TO MN THROUGH ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE CAN CAUSE NEUROTOXIC EFFECTS RESULTING IN MANGANISM, A CONDITION WITH CLINICAL SYMPTOMS IDENTICAL TO IDIOPATHIC PARKINSON'S DISEASE. EPIGENETICS IS NOW RECOGNIZED AS A BIOLOGICAL MECHANISM INVOLVED IN THE ETIOLOGY OF VARIOUS DISEASES. HERE, WE INVESTIGATED THE ROLE OF DNA METHYLATION ALTERATIONS INDUCED BY CHRONIC MN (100 MICROM) EXPOSURE IN HUMAN NEUROBLASTOMA (SH-SY5Y) CELLS IN RELEVANCE TO PARKINSON'S DISEASE. A COMBINED ANALYSIS OF DNA METHYLATION AND GENE EXPRESSION DATA FOR PARKINSON'S DISEASE-ASSOCIATED GENES WAS CARRIED OUT. WHOLE-GENOME BISULFITE CONVERSION AND SEQUENCING INDICATE EPIGENETIC PERTURBATION OF KEY GENES INVOLVED IN BIOLOGICAL PROCESSES ASSOCIATED WITH NEURONAL CELL HEALTH. INTEGRATION OF DNA METHYLATION DATA WITH GENE EXPRESSION REVEALS EPIGENETIC ALTERATIONS TO PINK1, PARK2 AND TH GENES THAT PLAY CRITICAL ROLES IN THE ONSET OF PARKINSONISM. THE PRESENT STUDY SUGGESTS THAT MN-INDUCED ALTERATION OF DNA METHYLATION OF PINK1-PARK2 MAY INFLUENCE MITOCHONDRIAL FUNCTION AND PROMOTE PARKINSONISM. OUR FINDINGS PROVIDE A BASIS TO FURTHER EXPLORE AND VALIDATE THE EPIGENETIC BASIS OF MN-INDUCED NEUROTOXICITY . 2017 7 3345 31 HISTONE DEACETYLASES AS EPIGENETIC TARGETS FOR TREATING PARKINSON'S DISEASE. PARKINSON'S DISEASE (PD) IS A CHRONIC PROGRESSIVE NEURODEGENERATIVE DISEASE THAT IS INCREASINGLY BECOMING A GLOBAL THREAT TO THE HEALTH AND LIFE OF THE ELDERLY WORLDWIDE. ALTHOUGH THERE ARE SOME DRUGS CLINICALLY AVAILABLE FOR TREATING PD, THESE TREATMENTS CAN ONLY ALLEVIATE THE SYMPTOMS OF PD PATIENTS BUT CANNOT COMPLETELY CURE THE DISEASE. THEREFORE, EXPLORING OTHER POTENTIAL MECHANISMS TO DEVELOP MORE EFFECTIVE TREATMENTS THAT CAN MODIFY THE COURSE OF PD IS STILL HIGHLY DESIRABLE. OVER THE LAST TWO DECADES, HISTONE DEACETYLASES, AS AN IMPORTANT GROUP OF EPIGENETIC TARGETS, HAVE ATTRACTED MUCH ATTENTION IN DRUG DISCOVERY. THIS REVIEW FOCUSED ON THE CURRENT KNOWLEDGE ABOUT HISTONE DEACETYLASES INVOLVED IN PD PATHOPHYSIOLOGY AND THEIR INHIBITORS USED IN PD STUDIES. FURTHER PERSPECTIVES RELATED TO SMALL MOLECULES THAT CAN INHIBIT OR DEGRADE HISTONE DEACETYLASES TO TREAT PD WERE ALSO DISCUSSED. 2022 8 330 31 ALPHA-SYNUCLEIN AND MECHANISMS OF EPIGENETIC REGULATION. SYNUCLEINOPATHIES ARE A GROUP OF NEURODEGENERATIVE DISEASES WITH COMMON PATHOLOGICAL LESIONS ASSOCIATED WITH THE EXCESSIVE ACCUMULATION AND ABNORMAL INTRACELLULAR DEPOSITION OF TOXIC SPECIES OF ALPHA-SYNUCLEIN. THE SHARED CLINICAL FEATURES ARE CHRONIC PROGRESSIVE DECLINE OF MOTOR, COGNITIVE, AND BEHAVIORAL FUNCTIONS. THESE DISORDERS INCLUDE PARKINSON'S DISEASE, DEMENTIA WITH LEWY BODY, AND MULTIPLE SYSTEM ATROPHY. VIGOROUS RESEARCH IN THE MECHANISMS OF PATHOLOGY OF THESE ILLNESSES IS CURRENTLY UNDER WAY TO FIND DISEASE-MODIFYING TREATMENT AND MOLECULAR MARKERS FOR EARLY DIAGNOSIS. ALPHA-SYNUCLEIN IS A PRONE-TO-AGGREGATE, SMALL AMYLOIDOGENIC PROTEIN WITH MULTIPLE ROLES IN SYNAPTIC VESICLE TRAFFICKING, NEUROTRANSMITTER RELEASE, AND INTRACELLULAR SIGNALING EVENTS. ITS EXPRESSION IS CONTROLLED BY SEVERAL MECHANISMS, ONE OF WHICH IS EPIGENETIC REGULATION. WHEN TRANSMITTED TO THE NUCLEUS, ALPHA-SYNUCLEIN BINDS TO DNA AND HISTONES AND PARTICIPATES IN EPIGENETIC REGULATORY FUNCTIONS CONTROLLING SPECIFIC GENE TRANSCRIPTION. HERE, WE DISCUSS THE VARIOUS ASPECTS OF ALPHA-SYNUCLEIN INVOLVEMENT IN EPIGENETIC REGULATION IN HEALTH AND DISEASES. 2023 9 6904 21 [THE ROLE OF ALUMINUM AND LEAD IN THE DEVELOPMENT OF ALZHEIMER'S AND PARKINSON'S DISEASES]. THE ARTICLE SUMMARIZES THE DATA AVAILABLE IN THE LITERATURE ON THE TOXIC EFFECTS OF ALUMINUM AND LEAD ON THE HUMAN BRAIN AND ASSESSES THE RELATIONSHIP OF THESE EFFECTS TO THE ETIOPATHOGENESIS OF THE MOST COMMON NEURODEGENERATIVE DISEASES, SUCH AS ALZHEIMER'S AND PARKINSON'S DISEASES. THE ACCUMULATION OF IONS OF THESE METALS IN THE BRAIN STRUCTURES LEADS TO CHRONIC INTOXICATION THAT IS MANIFESTED BY THE MORPHOLOGICAL SIGNS THAT ARE TYPICAL FOR ALZHEIMER'S DISEASE, SUCH AS DEPOSITS OF BETA-AMYLOID AND TAU-PROTEIN MAINLY IN THE FRONTAL AND TEMPORAL REGIONS OF THE CORTEX, AND FOR PARKINSON'S DISEASE, SUCH AS DEGENERATION OF DOPAMINE NEURONS IN THE SUBSTANTIA NIGRA AND THEIR ACCUMULATION OF ALPHA-SYNUCLEIN. THE MOST LIKELY FORMS OF PARTICIPATION OF ALUMINUM AND LEAD IONS IN THE MECHANISMS OF NEURODEGENERATION ARE THE REPLACEMENT OF BIVALENT METAL IONS NECESSARY FOR BRAIN FUNCTIONING, OXIDATIVE STRESS INITIATION, EPIGENETIC MODIFICATIONS OF HISTONES, AND INCREASED EXPRESSION OF NONCODING RIBONUCLEIC ACIDS. 2021 10 6889 18 [S-ADENOSYL L-METHIONINE IN CNS DISEASES]. S-ADENOSYL L-METHIONINE (SAME) IS THE NATURAL, UNIVERSAL METHYL GROUP DONOR, PARTICIPATING IN TRANSMETHYLATION REACTIONS, KNOWN AND COMMONLY USED AS A DIETARY SUPPLEMENT SINCE 1952. IT PLAYS AN IMPORTANT ROLE IN THE SYNTHESIS OF NEUROMEDIATORS AND MELATONIN AND MECHANISMS OF EPIGENETIC REGULATION. THE AIM OF THIS ARTICLE IS TO REVIEW THE LITERATURE ABOUT POSSIBILITIES OF SAME APPLICATION IN THE THERAPY OF CNS DISEASES: DEPRESSION, DEMENTIA SYNDROMES, SCHIZOPHRENIA AND SOMATIC DISORDERS. SAME IS THE PROMISING DIETARY SUPPLEMENT, WHICH MAY BE SUCCESSFULLY USED AS A SUBSTANCE INCREASING EFFECTIVENESS OF THE TREATMENT OF DEPRESSION, WITH ANTIDEPRESSANTS IN MONOTHERAPY IN MILD DEPRESSIVE STATES OR DEPRESSIVE SYMPTOMS. SAME ADDITION TO ANTIPSYCHOTIC DRUG, MAY LEAD TO THE IMPROVEMENT OF THE QUALITY OF LIFE AND REDUCTION OF AGGRESSIVENESS OF PATIENTS. SAME MAY BE AN EFFECTIVE SUBSTANCE IN THE THERAPY AND PROPHYLAXIS OF MILD COGNITIVE IMPAIRMENTS AND MILD DEMENTIA SYNDROME. SAME POSSESSES SOME HEPATOPROTECTIVE ACTION, SO IT MAY DECREASE THE RISK OF THE DEVELOPMENT OF NEOPLASM, ALCOHOL-INDUCED LIVER DISEASE (ALD) AND CIRRHOSIS. SAME IMPROVES THE FUNCTIONS OF JOINTS AND DECREASES THE EXPERIENCE OF PAIN IN RHEUMATOID ARTHRITIS (RA). 2011 11 6174 43 THE HIPPOCAMPUS, NEUROTROPHIC FACTORS AND DEPRESSION: POSSIBLE IMPLICATIONS FOR THE PHARMACOTHERAPY OF DEPRESSION. DEPRESSION IS A PREVALENT, HIGHLY DEBILITATING MENTAL DISORDER AFFECTING UP TO 15% OF THE POPULATION AT LEAST ONCE IN THEIR LIFETIME, WITH HUGE COSTS FOR SOCIETY. NEUROBIOLOGICAL MECHANISMS OF DEPRESSION ARE STILL NOT WELL KNOWN, ALTHOUGH THERE IS CONSENSUS ABOUT INTERPLAY BETWEEN GENETIC AND ENVIRONMENTAL FACTORS. ANTIDEPRESSANT MEDICATIONS ARE FREQUENTLY USED IN DEPRESSION, BUT AT LEAST 50% OF PATIENTS ARE POOR RESPONDERS, EVEN TO MORE RECENTLY DISCOVERED MEDICATIONS. FURTHERMORE, CLINICAL RESPONSE ONLY OCCURS FOLLOWING WEEKS TO MONTHS OF TREATMENT AND ONLY CHRONIC TREATMENT IS EFFECTIVE, SUGGESTING THAT ACTIONS BEYOND THE RAPIDLY OCCURRING EFFECT OF ENHANCING MONOAMINERGIC SYSTEMS, SUCH AS ADAPTATION OF THESE SYSTEMS, ARE RESPONSIBLE FOR THE EFFECTS OF ANTIDEPRESSANTS. RECENT STUDIES INDICATE THAT AN IMPAIRMENT OF SYNAPTIC PLASTICITY (NEUROGENESIS, AXON BRANCHING, DENDRITOGENESIS AND SYNAPTOGENESIS) IN SPECIFIC AREAS OF THE CNS, PARTICULARLY THE HIPPOCAMPUS, MAY BE A CORE FACTOR IN THE PATHOPHYSIOLOGY OF DEPRESSION. THE ABNORMAL NEURAL PLASTICITY MAY BE RELATED TO ALTERATIONS IN THE LEVELS OF NEUROTROPHIC FACTORS, NAMELY BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), WHICH PLAY A CENTRAL ROLE IN PLASTICITY. AS BDNF IS REPRESSED BY STRESS, EPIGENETIC REGULATION OF THE BDNF GENE MAY PLAY AN IMPORTANT ROLE IN DEPRESSION. THE HIPPOCAMPUS IS SMALLER IN DEPRESSED PATIENTS, ALTHOUGH IT IS UNCLEAR WHETHER SMALLER SIZE IS A CONSEQUENCE OF DEPRESSION OR A PRE-EXISTING, VULNERABILITY MARKER FOR DEPRESSION. ENVIRONMENTAL STRESSORS TRIGGERING ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS CAUSE THE BRAIN TO BE EXPOSED TO CORTICOSTEROIDS, AFFECTING NEUROBEHAVIOURAL FUNCTIONS WITH A STRONG DOWNREGULATION OF HIPPOCAMPAL NEUROGENESIS, AND ARE A MAJOR RISK FACTOR FOR DEPRESSION. ANTIDEPRESSANT TREATMENT INCREASES BDNF LEVELS, STIMULATES NEUROGENESIS AND REVERSES THE INHIBITORY EFFECTS OF STRESS, BUT THIS EFFECT IS EVIDENT ONLY AFTER 3-4 WEEKS OF ADMINISTRATION, THE TIME COURSE FOR MATURATION OF NEW NEURONS. THE ABLATION OF HIPPOCAMPAL NEUROGENESIS BLOCKS THE BEHAVIOURAL EFFECTS OF ANTIDEPRESSANTS IN ANIMAL MODELS. THE ABOVE FINDINGS SUGGEST NEW POSSIBLE TARGETS FOR THE PHARMACOTHERAPY OF DEPRESSION SUCH AS NEUROTROPHIC FACTORS, THEIR RECEPTORS AND RELATED INTRACELLULAR SIGNALLING CASCADES; AGENTS COUNTERACTING THE EFFECTS OF STRESS ON HIPPOCAMPAL NEUROGENESIS (INCLUDING ANTAGONISTS OF CORTICOSTEROIDS, INFLAMMATORY CYTOKINES AND THEIR RECEPTORS); AND AGENTS FACILITATING THE ACTIVATION OF GENE EXPRESSION AND INCREASING THE TRANSCRIPTION OF NEUROTROPHINS IN THE BRAIN. 2011 12 4206 40 METABOTROPIC GLUTAMATE 2/3 RECEPTORS AND EPIGENETIC MODIFICATIONS IN PSYCHOTIC DISORDERS: A REVIEW. SCHIZOPHRENIA AND BIPOLAR DISORDER ARE CHRONIC PSYCHIATRIC DISORDERS, BOTH CONSIDERED AS "MAJOR PSYCHOSIS"; THEY ARE THOUGHT TO SHARE SOME PATHOGENETIC FACTORS INVOLVING A DYSFUNCTIONAL GENE X ENVIRONMENT INTERACTION. ALTERATIONS IN THE GLUTAMATERGIC TRANSMISSION HAVE BEEN SUGGESTED TO BE INVOLVED IN THE PATHOGENESIS OF PSYCHOSIS. OUR GROUP DEVELOPED AN EPIGENETIC MODEL OF SCHIZOPHRENIA ORIGINATED BY PRENATAL RESTRAINT STRESS (PRS) PARADIGM IN MICE. PRS MICE DEVELOPED SOME BEHAVIORAL ALTERATIONS OBSERVED IN SCHIZOPHRENIC PATIENTS AND CLASSIC ANIMAL MODELS OF SCHIZOPHRENIA, I.E. DEFICITS IN SOCIAL INTERACTION, LOCOMOTOR ACTIVITY AND PREPULSE INHIBITION. THEY ALSO SHOWED SPECIFIC CHANGES IN PROMOTER DNA METHYLATION ACTIVITY OF GENES RELATED TO SCHIZOPHRENIA SUCH AS REELIN, BDNF AND GAD67, AND ALTERED EXPRESSION AND FUNCTION OF MGLU2/3 RECEPTORS IN THE FRONTAL CORTEX. INTERESTINGLY, BEHAVIORAL AND MOLECULAR ALTERATIONS WERE REVERSED BY TREATMENT WITH MGLU2/3 AGONISTS. BASED ON THESE FINDINGS, WE SPECULATE THAT PHARMACOLOGICAL MODULATION OF THESE RECEPTORS COULD HAVE A GREAT IMPACT ON EARLY PHASE TREATMENT OF PSYCHOSIS TOGETHER WITH THE POSSIBILITY TO MODULATE SPECIFIC EPIGENETIC KEY PROTEIN INVOLVED IN THE DEVELOPMENT OF PSYCHOSIS. IN THIS REVIEW, WE WILL DISCUSS IN MORE DETAILS THE SPECIFIC FEATURES OF THE PRS MICE AS A SUITABLE EPIGENETIC MODEL FOR MAJOR PSYCHOSIS. WE WILL THEN FOCUS ON KEY PROTEINS OF CHROMATIN REMODELING MACHINERY AS POTENTIAL TARGET FOR NEW PHARMACOLOGICAL TREATMENT THROUGH THE ACTIVATION OF METABOTROPIC GLUTAMATE RECEPTORS. 2016 13 2740 31 EXPOSURE TO EARLY LIFE STRESS RESULTS IN EPIGENETIC CHANGES IN NEUROTROPHIC FACTOR GENE EXPRESSION IN A PARKINSONIAN RAT MODEL. EARLY LIFE ADVERSITY INCREASES THE RISK OF MENTAL DISORDERS LATER IN LIFE. CHRONIC EARLY LIFE STRESS MAY ALTER NEUROTROPHIC FACTOR GENE EXPRESSION INCLUDING THOSE FOR BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) AND GLIAL CELL DERIVED NEUROTROPHIC FACTOR (GDNF) THAT ARE IMPORTANT IN NEURONAL GROWTH, SURVIVAL, AND MAINTENANCE. MATERNAL SEPARATION WAS USED IN THIS STUDY TO MODEL EARLY LIFE STRESS. FOLLOWING UNILATERAL INJECTION OF A MILD DOSE OF 6-HYDROXYDOPAMINE (6-OHDA), WE MEASURED CORTICOSTERONE (CORT) IN THE BLOOD AND STRIATUM OF STRESSED AND NONSTRESSED RATS; WE ALSO MEASURED DNA METHYLATION AND BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM USING REAL TIME PCR. IN THE PRESENCE OF STRESS, WE FOUND THAT THERE WAS INCREASED CORTICOSTERONE CONCENTRATION IN BOTH BLOOD AND STRIATAL TISSUE. FURTHER TO THIS, WE FOUND HIGHER DNA METHYLATION AND DECREASED NEUROTROPHIC FACTOR GENE EXPRESSION. 6-OHDA LESION INCREASED NEUROTROPHIC FACTOR GENE EXPRESSION IN BOTH STRESSED AND NONSTRESSED RATS BUT THIS INCREASE WAS HIGHER IN THE NONSTRESSED RATS. OUR RESULTS SUGGEST THAT EXPOSURE TO EARLY POSTNATAL STRESS INCREASES CORTICOSTERONE CONCENTRATION WHICH LEADS TO INCREASED DNA METHYLATION. THIS EFFECT RESULTS IN DECREASED BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM LEADING TO DECREASED PROTECTION AGAINST SUBSEQUENT INSULTS LATER IN LIFE. 2016 14 2598 30 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 15 5427 30 REGULATION OF SOCIAL STRESS AND NEURAL DEGENERATION BY ACTIVITY-REGULATED GENES AND EPIGENETIC MECHANISMS IN DOPAMINERGIC NEURONS. TRANSCRIPTIONAL AND EPIGENETIC REGULATION OF BOTH DOPAMINERGIC NEURONS AND THEIR ACCOMPANYING GLIAL CELLS IS OF GREAT INTEREST IN THE SEARCH FOR THERAPIES FOR NEURODEGENERATIVE DISORDERS SUCH AS PARKINSON'S DISEASE (PD). IN THIS REVIEW, WE COLLATE TRANSCRIPTIONAL AND EPIGENETIC CHANGES IDENTIFIED IN ADULT DROSOPHILA MELANOGASTER DOPAMINERGIC NEURONS IN RESPONSE TO EITHER PROLONGED SOCIAL DEPRIVATION OR SOCIAL ENRICHMENT, AND COMPARE THEM WITH CHANGES IDENTIFIED IN MAMMALIAN DOPAMINERGIC NEURONS DURING NORMAL DEVELOPMENT, STRESS, INJURY, AND NEURODEGENERATION. SURPRISINGLY, A SMALL SET OF ACTIVITY-REGULATED GENES (ARG) ENCODING TRANSCRIPTION FACTORS, AND A SPECIFIC PATTERN OF EPIGENETIC MARKS ON GENE PROMOTERS, ARE CONSERVED IN DOPAMINERGIC NEURONS OVER THE LONG EVOLUTIONARY PERIOD BETWEEN MAMMALS AND INSECTS. IN ADDITION TO THEIR CLASSICAL FUNCTION AS IMMEDIATE EARLY GENES TO MARK ACUTE NEURONAL ACTIVITY, THESE ARG TRANSCRIPTION FACTORS ARE REPURPOSED IN BOTH INSECTS AND MAMMALS TO RESPOND TO CHRONIC PERTURBATIONS SUCH AS SOCIAL ENRICHMENT, SOCIAL STRESS, NERVE INJURY, AND NEURODEGENERATION. WE SUGGEST THAT THESE ARG TRANSCRIPTION FACTORS AND EPIGENETIC MARKS MAY REPRESENT IMPORTANT TARGETS FOR FUTURE THERAPEUTIC INTERVENTION STRATEGIES IN VARIOUS NEURODEGENERATIVE DISORDERS INCLUDING PD. 2020 16 4642 37 NEURONAL PLASTICITY: A LINK BETWEEN STRESS AND MOOD DISORDERS. ALTHOUGH STRESS REPRESENTS THE MAJOR ENVIRONMENTAL ELEMENT OF SUSCEPTIBILITY FOR MOOD DISORDERS, THE RELATIONSHIP BETWEEN STRESS AND DISEASE REMAINS TO BE FULLY ESTABLISHED. IN THE PRESENT ARTICLE WE REVIEW THE EVIDENCE IN SUPPORT FOR A ROLE OF NEURONAL PLASTICITY, AND IN PARTICULAR OF NEUROTROPHIC FACTORS. EVEN THOUGH DECREASED LEVELS OF NOREPINEPHRINE AND SEROTONIN MAY UNDERLIE DEPRESSIVE SYMPTOMS, COMPELLING EVIDENCE NOW SUGGESTS THAT MOOD DISORDERS ARE CHARACTERIZED BY REDUCED NEURONAL PLASTICITY, WHICH CAN BE BROUGHT ABOUT BY EXPOSURE TO STRESS AT DIFFERENT STAGES OF LIFE. INDEED THE EXPRESSION OF NEUROTROPHIC MOLECULES, SUCH AS THE NEUROTROPHIN BDNF, IS REDUCED IN DEPRESSED SUBJECTS AS WELL AS IN EXPERIMENTAL ANIMALS EXPOSED TO ADVERSE EXPERIENCE AT EARLY STAGES OF LIFE OR AT ADULTHOOD. THESE CHANGES SHOW AN ANATOMICAL SPECIFICITY AND MIGHT BE SUSTAINED BY EPIGENETIC MECHANISMS. PHARMACOLOGICAL INTERVENTION MAY NORMALIZE SUCH DEFECTS AND IMPROVE NEURONAL FUNCTION THROUGH THE MODULATION OF THE SAME FACTORS THAT ARE DEFECTIVE IN DEPRESSION. SEVERAL STUDIES HAVE DEMONSTRATED THAT CHRONIC, BUT NOT ACUTE, ANTIDEPRESSANT TREATMENT INCREASES THE EXPRESSION OF BDNF AND MAY ENHANCE ITS LOCALIZATION AT SYNAPTIC LEVEL. ANTIDEPRESSANT TREATMENT CAN NORMALIZE DEFICITS IN NEUROTROPHIN EXPRESSION PRODUCED BY CHRONIC STRESS PARADIGMS, BUT MAY ALSO ALTER THE MODULATION OF BDNF UNDER ACUTE STRESSFUL CONDITIONS. IN SUMMARY, THERE IS GOOD AGREEMENT IN CONSIDERING NEURONAL PLASTICITY, AND THE EXPRESSION OF KEY PROTEINS SUCH AS THE NEUROTROPHIN BDNF, AS A CENTRAL PLAYER FOR THE EFFECTS OF STRESS ON BRAIN FUNCTION AND ITS IMPLICATION FOR PSYCHOPATHOLOGY. ACCORDINGLY, EFFECTIVE TREATMENTS SHOULD NOT LIMIT THEIR EFFECTS TO THE CONTROL OF NEUROTRANSMITTER AND HORMONAL DYSFUNCTIONS, BUT SHOULD BE ABLE TO NORMALIZE DEFECTIVE MECHANISMS THAT SUSTAIN THE IMPAIRMENT OF NEURONAL PLASTICITY. 2009 17 6061 26 THE DEVELOPMENT PROSPECTION OF HDAC INHIBITORS AS A POTENTIAL THERAPEUTIC DIRECTION IN ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISEASE, WHICH IS ASSOCIATED WITH LEARNING AND MEMORY IMPAIRMENT IN THE ELDERLY. RECENT STUDIES HAVE FOUND THAT TREATING AD IN THE WAY OF CHROMATIN REMODELING VIA HISTONE ACETYLATION IS A PROMISING THERAPEUTIC REGIMEN. IN A NUMBER OF RECENT STUDIES, INHIBITORS OF HISTONE DEACETYLASE (HDACS) HAVE BEEN FOUND TO BE A NOVEL PROMISING THERAPEUTIC AGENTS FOR NEUROLOGICAL DISORDERS, PARTICULARLY FOR AD AND OTHER NEURODEGENERATIVE DISEASES. ALTHOUGH HDAC INHIBITORS HAVE THE ABILITY TO AMELIORATE COGNITIVE IMPAIRMENT, SUCCESSFUL TREATMENTS IN THE CLASSIC AD ANIMAL MODEL ARE RARELY TRANSLATED INTO CLINICAL TRIALS. AS FOR THE REDUCTION OF UNWANTED SIDE EFFECTS, THE DEVELOPMENT OF HDAC INHIBITORS WITH INCREASED ISOFORM SELECTIVITY OR SEEKING OTHER DIRECTIONS IS A KEY ISSUE THAT NEEDS TO BE ADDRESSED. THE REVIEW FOCUSED ON LITERATURES ON EPIGENETIC MECHANISMS IN RECENT YEARS, ESPECIALLY ON HISTONE ACETYLATION IN TERMS OF THE ENHANCEMENT OF SPECIFICITY, EFFICACY AND AVOIDING SIDE EFFECTS FOR TREATING AD. 2017 18 966 36 CHRONIC NEUROLOGICAL DISORDERS: GENETIC AND EPIGENETIC MARKERS FOR MONITORING OF PHARMACOTHERAPY. INTRODUCTION: CHRONIC NEUROLOGICAL DISEASES ARE A MAJOR CAUSE OF MORTALITY AND MORBIDITY IN THE WORLD. WITH INCREASING LIFE EXPECTANCY IN THE DEVELOPING WORLD, THE INCIDENCE AND PREVALENCE OF THESE DISEASES ARE PREDICTED TO RISE EVEN FURTHER. THIS HAS ALSO CONTRIBUTED TO AN INCREASE IN DISABILITY-ADJUSTED LIFE YEARS (DALYS) FOR NONCOMMUNICABLE DISEASES. TREATMENT FOR SUCH DISEASES ALSO POSES A CHALLENGE WITH MULTIPLE GENETIC AND EPIGENETIC FACTORS LEADING TO A VARIED OUTCOME. PERSONALIZATION OF TREATMENT IS ONE WAY THAT TREATMENT OUTCOME/PROGNOSIS OF DISEASE CAN BE IMPROVED, AND PHARMACOGENOMICS PLAYS A SIGNIFICANT ROLE IN THIS CONTEXT. METHODOLOGY: THIS ARTICLE REVIEWED THE EVIDENCE PERTAINING TO THE ASSOCIATION OF GENETIC AND EPIGENETIC MARKERS WITH MAJOR NEUROLOGICAL DISORDERS LIKE MULTIPLE SCLEROSIS (MS), ALZHEIMER'S DISEASE (AD), AND PARKINSON'S DISEASE (PD), WHICH ARE A MAJOR SOURCE OF BURDEN AMONG NEUROLOGICAL DISORDERS. TYPES OF STUDIES INCLUDED ARE PEER-REVIEWED ORIGINAL RESEARCH ARTICLES FROM THE PUBMED DATABASE (1999-2018). RESULTS: THIS STUDY COMPILED DATA REGARDING SPECIFIC GENETIC AND EPIGENETIC MARKERS WITH A SIGNIFICANT CORRELATION BETWEEN THE CLINICAL DIAGNOSIS OF THE DISEASE AND PROGNOSIS OF THERAPY FROM 65 STUDIES. IN A SINGLE PLATFORM, THIS REVIEW HIGHLIGHTS THE CLUES TO SOME VITAL QUESTIONS, SUCH AS WHY INTERFERON BETA (IFN-BETA) THERAPY FAILS TO IMPROVE SYMPTOMS IN ALL MS PATIENTS? WHY CHOLINESTERASE INHIBITORS FAIL TO IMPROVE COGNITIVE IMPAIRMENT IN A SUBSET OF PEOPLE SUFFERING FROM AD? OR WHY SOME INDIVIDUALS ON LEVODOPA (L-DOPA) FOR PD SUFFER FROM SIDE-EFFECTS RANGING FROM DYSKINESIA TO HALLUCINATION WHILE OTHERS DO NOT? CONCLUSION: THIS ARTICLE SUMMARIZES THE GENETIC AND EPIGENETIC FACTORS THAT MAY EITHER REQUIRE MONITORING OR HELP IN DECIDING FUTURE PHARMACOTHERAPY IN A PATIENT SUFFERING FROM MS, AD, AND PD. AS THE HEALTH CARE SYSTEM DEVELOPS AND REACHES NEWER HEIGHTS, WE EXPECT MORE AND MORE OF THESE BIOMARKERS TO BE USED AS PHARMACOTHERAPEUTIC OUTCOME INDICATORS. 2021 19 4648 35 NEUROPEPTIDE Y IN ALCOHOL ADDICTION AND AFFECTIVE DISORDERS. NEUROPEPTIDE Y (NPY), A NEUROPEPTIDE HIGHLY CONSERVED THROUGHOUT EVOLUTION, IS PRESENT AT HIGH LEVELS IN THE CENTRAL NERVOUS SYSTEM (CNS), AS WELL AS IN PERIPHERAL TISSUES SUCH AS THE GUT AND CARDIOVASCULAR SYSTEM. THE PEPTIDE EXERTS ITS EFFECTS VIA MULTIPLE RECEPTOR SUBTYPES, ALL BELONGING TO THE G-PROTEIN-COUPLED RECEPTOR SUPERFAMILY. OF THESE SUBTYPES, THE Y1 AND THE Y2 ARE THE MOST THOROUGHLY CHARACTERIZED, FOLLOWED BY THE Y5 SUBTYPE. NPY AND ITS RECEPTORS HAVE BEEN SHOWN TO BE OF IMPORTANCE IN CENTRAL REGULATION OF EVENTS UNDERLYING, FOR EXAMPLE, AFFECTIVE DISORDERS, DRUG/ALCOHOL USE DISORDERS, AND ENERGY HOMEOSTASIS. FURTHERMORE, WITHIN THE CNS, NPY ALSO AFFECTS SLEEP REGULATION AND CIRCADIAN RHYTHM, MEMORY FUNCTION, TISSUE GROWTH, AND PLASTICITY. THE POTENTIAL ROLES OF NPY IN THE ETIOLOGY AND PATHOPHYSIOLOGY OF MOOD AND ANXIETY DISORDERS, AS WELL AS ALCOHOL USE DISORDERS, HAVE BEEN EXTENSIVELY STUDIED. THIS FOCUS WAS PROMPTED BY EARLY INDICATIONS FOR AN INVOLVEMENT OF NPY IN ACUTE RESPONSES TO STRESS, AND, LATER, ALSO DATA POINTING TO A ROLE IN ALTERATIONS WITHIN THE CNS DURING CHRONIC, OR REPEATED, EXPOSURE TO ADVERSE EVENTS. THESE FUNCTIONS OF NPY, IN ADDITION TO THE PEPTIDE'S REGULATION OF DISEASE STATES, SUGGEST THAT MODULATION OF THE ACTIVITY OF THE NPY SYSTEM VIA RECEPTOR AGONISTS/ANTAGONISTS MAY BE A PUTATIVE TREATMENT MECHANISM IN AFFECTIVE DISORDERS AS WELL AS ALCOHOL USE DISORDERS. IN THIS REVIEW, WE PRESENT AN OVERVIEW OF FINDINGS WITH REGARD TO THE NPY SYSTEM IN RELATION TO ANXIETY AND STRESS, ACUTE AS WELL AS CHRONIC; FURTHERMORE WE DISCUSS POST-TRAUMATIC STRESS DISORDER AND, IN PART DEPRESSION. IN ADDITION, WE SUMMARIZE FINDINGS ON ALCOHOL USE DISORDERS AND RELATED BEHAVIORS. FINALLY, WE BRIEFLY TOUCH UPON GENETIC AS WELL AS EPIGENETIC MECHANISMS THAT MAY BE OF IMPORTANCE FOR NPY FUNCTION AND REGULATION. IN CONCLUSION, WE SUGGEST THAT MODULATION OF NPY-ERGIC ACTIVITY WITHIN THE CNS, VIA LIGANDS AIMED AT DIFFERENT RECEPTOR SUBTYPES, MAY BE ATTRACTIVE TARGETS FOR TREATMENT DEVELOPMENT FOR AFFECTIVE DISORDERS, AS WELL AS FOR ALCOHOL USE DISORDERS. 2017 20 2489 28 EPIGENETICALLY MODIFIED NUCLEOTIDES IN CHRONIC HEROIN AND COCAINE TREATED MICE. EPIGENETIC CHANGES INCLUDE THE ADDITION OF A METHYL GROUP TO THE 5' CARBON OF THE CYTOSINE RING, KNOWN AS DNA METHYLATION, WHICH RESULTS IN THE GENERATION OF THE FIFTH DNA BASE, NAMELY 5-METHYLCYTOSINE. DURING ACTIVE OR PASSIVE DEMETHYLATION, AN INTERMEDIATE MODIFIED BASE IS FORMED, 5-HYDROXYMETHYLCYTOSINE. WE HAVE CURRENTLY QUANTIFIED 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE IN THE LIVER AND BRAIN OF MICE TREATED WITH COCAINE OR HEROIN, USING LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC-MS/MS). OUR RESULTS SHOW THAT GLOBAL 5-METHYLCYTOSINE LEVELS ARE NOT AFFECTED BY HEROIN OR COCAINE ADMINISTRATION, NEITHER IN THE LIVER NOR IN THE BRAIN. HOWEVER, 5-HYDROXYMETHYLCYTOSINE LEVELS ARE REDUCED IN THE LIVER FOLLOWING COCAINE ADMINISTRATION, WHILE THEY ARE NOT AFFECTED BY COCAINE IN THE BRAIN OR BY HEROIN ADMINISTRATION IN THE LIVER AND THE BRAIN. ELUCIDATION OF THE EPIGENETIC PHENOMENA THAT TAKES PLACE WITH RESPECT TO DRUG ABUSE AND ADDICTION, VIA QUANTITATIVE ANALYSIS OF DIFFERENT MODIFIED BASES, MAY ENABLE A BETTER UNDERSTANDING OF THE UNDERLYING MECHANISMS AND MAY LEAD TO MORE PERSONALIZED AND EFFECTIVE TREATMENT OPTIONS. 2014