1 889 119 CHRONIC DIETARY ADMINISTRATION OF VALPROIC ACID PROTECTS NEURONS OF THE RAT NUCLEUS BASALIS MAGNOCELLULARIS FROM IBOTENIC ACID NEUROTOXICITY. VALPROIC ACID (VPA) HAS BEEN USED FOR MANY YEARS AS A DRUG OF CHOICE FOR EPILEPSY AND MOOD DISORDERS. RECENTLY, EVIDENCE HAS BEEN PROPOSED FOR A WIDE SPECTRUM OF ACTIONS OF THIS DRUG, INCLUDING ANTITUMORAL AND NEUROPROTECTIVE PROPERTIES. VALPROIC ACID-MEDIATED NEUROPROTECTION IN VIVO HAS BEEN SO FAR DEMONSTRATED IN A LIMITED NUMBER OF EXPERIMENTAL MODELS. IN THIS STUDY, WE HAVE TESTED THE NEUROPROTECTIVE POTENTIAL OF CHRONIC (4 + 1 WEEKS) DIETARY ADMINISTRATION OF VPA ON DEGENERATION OF CHOLINERGIC AND GABAERGIC NEURONS OF THE RAT NUCLEUS BASALIS MAGNOCELLULARIS (NBM), INJECTED WITH THE EXCITOTOXIN, IBOTENIC ACID (IBO), AN ANIMAL MODELS THAT IS RELEVANT FOR ALZHEIMER'S DISEASE-LIKE NEURODEGENERATION. WE SHOW THAT VPA TREATMENT SIGNIFICANTLY PROTECTS BOTH CHOLINERGIC AND GABAERGIC NEURONS PRESENT IN THE INJECTED AREA FROM THE EXCITOTOXIC INSULT. A SIGNIFICANT LEVEL OF NEUROPROTECTION, IN PARTICULAR, IS EXERTED TOWARDS THE CHOLINERGIC NEURONS OF THE NBM PROJECTING TO THE CORTEX, AS DEMONSTRATED BY THE SUBSTANTIALLY HIGHER LEVELS OF CHOLINERGIC MARKERS MAINTAINED IN THE TARGET CORTICAL AREA OF VPA-TREATED RATS AFTER IBO INJECTION IN THE NBM. WE FURTHER SHOW THAT CHRONIC VPA ADMINISTRATION RESULTS IN INCREASED ACETYLATION OF HISTONE H3 IN BRAIN, CONSISTENT WITH THE HISTONE DEACETYLASE INHIBITORY ACTION OF VPA AND PUTATIVELY LINKED TO A NEUROPROTECTIVE ACTION OF THE DRUG MEDIATED AT THE EPIGENETIC LEVEL. 2009 2 2886 28 GABA-AALPHA5 MIGHT BE INVOLVED IN LEARNING-MEMORY DYSFUNCTION IN THE OFFSPRINGS OF CHRONIC ETHANOL-TREATED RATS VIA GABA-AALPHA5 HISTONE H3K9 ACETYLATION. RECENTLY, NUMEROUS STUDIES HAVE BEEN FOCUSED ON THE RELATIONSHIP BETWEEN GABA-A RECEPTORS AND ALCOHOL-INDUCED SPATIAL LEARNING AND MEMORY DEFICITS. GABA-AALPHA5, A SUBUNIT OF GABA-A RECEPTORS, IS CONSIDERED TO PLAY AN IMPORTANT ROLE IN ALCOHOL-INDUCED COGNITIVE IMPAIRMENT, HOWEVER, THE MECHANISM REMAINS OBSCURE. IN THIS STUDY, WE FOUND THAT THE EXPRESSION OF GABA-AALPHA5 INCREASED IN RATS TREATED WITH CHRONIC ETHANOL VIA HISTONE H3K9 ACETYLATION. FURTHERMORE, THIS EPIGENETIC MODIFICATION COULD BE INHERITED BY THE NEXT GENERATIONS, WHICH EVENTUALLY EXHIBIT SIMILAR SPATIAL LEARNING AND MEMORY DEFICITS IN THE OFFSPRINGS. IN SUMMARY, OUR RESULTS SUGGESTED THAT GABA-AALPHA5 MIGHT BE INVOLVED IN CHRONIC ETHANOL TREATMENT-INDUCED LEARNING-MEMORY DYSFUNCTION AND FOR THE FIRST TIME PROVED THAT LEARNING-MEMORY DYSFUNCTION COULD BE INHERITED BY THE OFFSPRINGS VIA HISTONE H3K9 ACETYLATION. HOPEFULLY, IN THE NEAR FUTURE, GABA-AALPHA5 INHIBITORS WOULD BE AN EFFECTIVE WAY TO TREAT ALCOHOL-INDUCED COGNITION IMPAIRMENT. 2019 3 2246 24 EPIGENETIC MODULATION OF INFLAMMATION AND SYNAPTIC PLASTICITY PROMOTES RESILIENCE AGAINST STRESS IN MICE. MAJOR DEPRESSIVE DISORDER IS ASSOCIATED WITH ABNORMALITIES IN THE BRAIN AND THE IMMUNE SYSTEM. CHRONIC STRESS IN ANIMALS SHOWED THAT EPIGENETIC AND INFLAMMATORY MECHANISMS PLAY IMPORTANT ROLES IN MEDIATING RESILIENCE AND SUSCEPTIBILITY TO DEPRESSION. HERE, THROUGH A HIGH-THROUGHPUT SCREENING, WE IDENTIFY TWO PHYTOCHEMICALS, DIHYDROCAFFEIC ACID (DHCA) AND MALVIDIN-3'-O-GLUCOSIDE (MAL-GLUC) THAT ARE EFFECTIVE IN PROMOTING RESILIENCE AGAINST STRESS BY MODULATING BRAIN SYNAPTIC PLASTICITY AND PERIPHERAL INFLAMMATION. DHCA/MAL-GLUC ALSO SIGNIFICANTLY REDUCES DEPRESSION-LIKE PHENOTYPES IN A MOUSE MODEL OF INCREASED SYSTEMIC INFLAMMATION INDUCED BY TRANSPLANTATION OF HEMATOPOIETIC PROGENITOR CELLS FROM STRESS-SUSCEPTIBLE MICE. DHCA REDUCES PRO-INFLAMMATORY INTERLEUKIN 6 (IL-6) GENERATIONS BY INHIBITING DNA METHYLATION AT THE CPG-RICH IL-6 SEQUENCES INTRONS 1 AND 3, WHILE MAL-GLUC MODULATES SYNAPTIC PLASTICITY BY INCREASING HISTONE ACETYLATION OF THE REGULATORY SEQUENCES OF THE RAC1 GENE. PERIPHERAL INFLAMMATION AND SYNAPTIC MALADAPTATION ARE IN LINE WITH NEWLY HYPOTHESIZED CLINICAL INTERVENTION TARGETS FOR DEPRESSION THAT ARE NOT ADDRESSED BY CURRENTLY AVAILABLE ANTIDEPRESSANTS. 2018 4 5474 34 RESTORATION OF HISTONE ACETYLATION AMELIORATES DISEASE AND METABOLIC ABNORMALITIES IN A FUS MOUSE MODEL. DYSREGULATION OF EPIGENETIC MECHANISMS IS EMERGING AS A CENTRAL EVENT IN NEURODEGENERATIVE DISORDERS, INCLUDING AMYOTROPHIC LATERAL SCLEROSIS (ALS). IN MANY MODELS OF NEURODEGENERATION, GLOBAL HISTONE ACETYLATION IS DECREASED IN THE AFFECTED NEURONAL TISSUES. HISTONE ACETYLATION IS CONTROLLED BY THE ANTAGONISTIC ACTIONS OF TWO PROTEIN FAMILIES -THE HISTONE ACETYLTRANSFERASES (HATS) AND THE HISTONE DEACETYLASES (HDACS). DRUGS INHIBITING HDAC ACTIVITY ARE ALREADY USED IN THE CLINIC AS ANTI-CANCER AGENTS. THE AIM OF THIS STUDY WAS TO EXPLORE THE THERAPEUTIC POTENTIAL OF HDAC INHIBITION IN THE CONTEXT OF ALS. WE DISCOVERED THAT TRANSGENIC MICE OVEREXPRESSING WILD-TYPE FUS ("TG FUS+/+"), WHICH RECAPITULATE MANY ASPECTS OF HUMAN ALS, SHOWED REDUCED GLOBAL HISTONE ACETYLATION AND ALTERATIONS IN METABOLIC GENE EXPRESSION, RESULTING IN A DYSREGULATED METABOLIC HOMEOSTASIS. CHRONIC TREATMENT OF TG FUS+/+ MICE WITH ACY-738, A POTENT HDAC INHIBITOR THAT CAN CROSS THE BLOOD-BRAIN BARRIER, AMELIORATED THE MOTOR PHENOTYPE AND SUBSTANTIALLY EXTENDED THE LIFE SPAN OF THE TG FUS+/+ MICE. AT THE MOLECULAR LEVEL, ACY-738 RESTORED GLOBAL HISTONE ACETYLATION AND METABOLIC GENE EXPRESSION, THEREBY RE-ESTABLISHING METABOLITE LEVELS IN THE SPINAL CORD. TAKEN TOGETHER, OUR FINDINGS LINK EPIGENETIC ALTERATIONS TO METABOLIC DYSREGULATION IN ALS PATHOLOGY, AND HIGHLIGHT ACY-738 AS A POTENTIAL THERAPEUTIC STRATEGY TO TREAT THIS DEVASTATING DISEASE. 2019 5 3325 30 HISTONE DEACETYLASE 2-MEDIATED EPIGENETIC REGULATION IS INVOLVED IN THE EARLY ISOFLURANE EXPOSURE-RELATED INCREASE IN SUSCEPTIBILITY TO ANXIETY-LIKE BEHAVIOUR EVOKED BY CHRONIC VARIABLE STRESS IN MICE. INCREASING STUDIES REPORT THAT PROLONGED OR MULTIPLE ANAESTHETIC EXPOSURES EARLY IN LIFE ARE ASSOCIATED WITH DETRIMENTAL EFFECTS ON BRAIN FUNCTION. ALTHOUGH STUDIES HAVE EVALUATED THE DETRIMENTAL EFFECTS ON NEUROCOGNITIVE FUNCTION, FEW HAVE FOCUSED ON LONG-TERM NEUROPSYCHIATRIC EFFECTS. IN THE PRESENT STUDY, C57BL/6 MICE RECEIVED EITHER THREE NEONATAL ISOFLURANE EXPOSURES OR CONTROL EXPOSURE. STARTING ON POSTNATAL DAY 45, THE MICE WERE EITHER EXPOSED OR NOT TO A CHRONIC VARIABLE STRESS (CVS) PARADIGM, AND CVS-RELATED NEUROPSYCHIATRIC PERFORMANCE WAS EVALUATED USING A SERIES OF BEHAVIOURAL TESTS. THE EXPRESSION LEVELS OF HISTONE 3 LYSINE 9 ACETYLATION (ACETYL-H3K9), BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), CAMP RESPONSE ELEMENT-BINDING PROTEIN-BINDING PROTEIN, AND HISTONE DEACETYLASES 1-4 IN THE AMYGDALA WERE MEASURED BY IMMUNOBLOTTING OR IMMUNOHISTOCHEMISTRY ANALYSIS. IN MICE WITH NEONATAL ISOFLURANE EXPOSURE, THE EFFECTS OF SODIUM BUTYRATE (NAB), A COMMONLY USED HDAC INHIBITOR, WERE EXAMINED ON CVS-RELATED BEHAVIOURAL AND MOLECULAR ALTERATIONS. THE RESULTS SHOWED THAT REPEATED NEONATAL ISOFLURANE EXPOSURE DID NOT AFFECT INNATE DEPRESSION-LIKE AND ANXIETY-LIKE BEHAVIOURS UNDER NON-STRESS CONDITIONS BUT FACILITATED THE CVS-INDUCED ANXIETY-LIKE BEHAVIOURAL PHENOTYPE. INCREASED HDAC2 EXPRESSION IN THE AMYGDALA WAS ASSOCIATED WITH AN INCREASE IN THE CVS-INDUCED REPRESSION OF ACETYL-H3K9 AND BDNF EXPRESSION AND AN ENHANCED CVS-EVOKED ANXIETY-LIKE BEHAVIOURAL PHENOTYPE IN MICE NEONATAL ISOFLURANE EXPOSURE. NAB SIGNIFICANTLY DECREASED THE CVS-INDUCED ANXIETY LEVEL BY ELEVATING ACETYL-H3K9 AND BDNF EXPRESSION. THESE RESULTS SUGGESTED THAT EARLY ANAESTHESIA EXPOSURE FACILITATED CHRONIC STRESS-INDUCED NEUROPSYCHIATRIC OUTCOMES, AND THE HDAC2-RELATED EPIGENETIC DYSREGULATION OF BDNF GENE EXPRESSION IS INVOLVED IN THE UNDERLYING MECHANISM. 2021 6 5713 37 SIRT2 INHIBITION REVERSES ANHEDONIA IN THE VGLUT1+/- DEPRESSION MODEL. SOME HISTONE DEACETYLASE (HDACS) ENZYMES HAVE BEEN PROPOSED AS EPIGENETIC TARGETS INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSION AND ANTIDEPRESSANT-LIKE ACTION. AMONG THEM, WE HAVE RECENTLY IDENTIFIED SIRT2, A CLASS III NAD(+)-DEPENDENT HDAC, AS BEING OPPOSITELY REGULATED BY STRESS AND ANTIDEPRESSANTS. MOREOVER, SIRT2 INHIBITION HAS SHOWN ANTIANHEDONIC-LIKE ACTION IN THE CHRONIC MILD STRESS MODEL OF DEPRESSION. HERE WE HAVE EXTENDED THE STUDY USING AN ALTERNATIVE MODEL OF DEPRESSION BASED IN A GENETIC MANIPULATION OF GLUTAMATE FUNCTION. SPECIFICALLY, MICE HETEROZYGOUS FOR THE VESICULAR GLUTAMATE TRANSPORTER 1 (VGLUT1+/-) WERE USED. FIRSTLY, MRNA EXPRESSION OF THE DIFFERENT MEMBERS OF THE HDAC SUPERFAMILY IN THE PREFRONTAL CORTEX (PFC) OF VGLUT1+/- MICE AND WT LITTERMATES WERE STUDIED BY RT-PCR. SECONDLY, THE EFFECT OF REPEATED TREATMENT WITH THE SELECTIVE SIRT2 INHIBITOR 33I AND THE ANTIDEPRESSANT IMIPRAMINE ON ANHEDONIC BEHAVIOUR OF VGLUT1+/- MICE WAS STUDIED BY WEEKLY MONITORING OF SUCROSE INTAKE. FURTHER, THE INTERACTION OF 33I TOWARDS SPECIFIC MONOAMINERGIC TARGETS SUCH AS SEROTONIN OR NORADRENALINE TRANSPORTERS AS WELL AS THE MONOAMINOOXIDASE ENZYME WAS STUDIED. THE MRNA OCCURANCE OF THE DIFFERENT MEMBERS OF HDAC SUPERFAMILY WAS NOT ALTERED IN THE PFC OF VGLUT1+/- MICE. WHILE REPEATED IMIPRAMINE SHOWED AN ANTI-ANHEDONIC ACTION IN BOTH VGLUT1+/- AND WT, THE SELECTIVE SIRT2 INHIBITOR 33I FULLY REVERSED ANHEDONIA OF VGLUT1+/-. FURTHER, 33I SHOWED NO INTERACTION WITH THE ABOVE MENTIONED MONOAMINERGIC MOLECULAR TARGETS. THESE RESULTS CONFIRM THAT SIRT2 INHIBITION IS ABLE TO REVERSE ANHEDONIA IN DIFFERENT ANIMAL MODELS AND HIGHLIGHT THE NEED TO FURTHER INVESTIGATE THE ROLE OF SIRT2 INHIBITORS AS NEW ANTIDEPRESSANT AGENTS. 2017 7 5339 29 QUETIAPINE TREATMENT REVERSES DEPRESSIVE-LIKE BEHAVIOR AND REDUCES DNA METHYLTRANSFERASE ACTIVITY INDUCED BY MATERNAL DEPRIVATION. STRESS IN EARLY LIFE HAS BEEN APPOINTED AS AN IMPORTANT PHENOMENON IN THE ONSET OF DEPRESSION AND POOR RESPONSE TO TREATMENT WITH CLASSICAL ANTIDEPRESSANTS. FURTHERMORE, CHILDHOOD TRAUMA TRIGGERS EPIGENETIC CHANGES, WHICH ARE ASSOCIATED WITH THE PATHOPHYSIOLOGY OF MAJOR DEPRESSIVE DISORDER (MDD). TREATMENT WITH ATYPICAL ANTIPSYCHOTICS SUCH AS QUETIAPINE, EXERTS THERAPEUTIC EFFECT FOR MDD PATIENTS AND INDUCES EPIGENETIC CHANGES. THIS STUDY AIMED TO ANALYZE THE EFFECT OF CHRONIC TREATMENT WITH QUETIAPINE (20MG/KG) ON DEPRESSIVE-LIKE BEHAVIOR OF RATS SUBMITTED TO MATERNAL DEPRIVATION (MD), AS WELL AS THE ACTIVITY OF HISTONE ACETYLATION BY THE ENZYMES HISTONE ACETYL TRANSFERASES (HAT) AND DEACETYLASES (HDAC) AND DNA METHYLATION, THROUGH DNA METHYLTRANSFERASE ENZYME (DNMT) IN THE PREFRONTAL CORTEX (PFC), NUCLEUS ACCUMBENS (NAC) AND HIPPOCAMPUS. MATERNALLY DEPRIVED RATS HAD A DEPRESSIVE-LIKE BEHAVIOR IN THE FORCED SWIMMING TEST AND AN INCREASE IN THE HDAC AND DNMT ACTIVITIES IN THE HIPPOCAMPUS AND NAC. TREATMENT WITH QUETIAPINE REVERSED DEPRESSIVE-LIKE BEHAVIOR AND REDUCED THE DNMT ACTIVITY IN THE HIPPOCAMPUS. THIS IS THE FIRST STUDY TO SHOW THE ANTIDEPRESSANT-LIKE EFFECT OF QUETIAPINE IN ANIMALS SUBJECTED TO MD AND A PROTECTIVE EFFECT BY QUETIAPINE IN REDUCING EPIGENETIC CHANGES INDUCED BY STRESS IN EARLY LIFE. THESE RESULTS REINFORCE AN IMPORTANT ROLE OF QUETIAPINE AS THERAPY FOR MDD. 2017 8 6690 35 VALPROIC ACID SILENCING OF ASCL1B/ASCL1 RESULTS IN THE FAILURE OF SEROTONERGIC DIFFERENTIATION IN A ZEBRAFISH MODEL OF FETAL VALPROATE SYNDROME. FETAL VALPROATE SYNDROME (FVS) IS CAUSED BY IN UTERO EXPOSURE TO THE DRUG SODIUM VALPROATE. VALPROATE IS USED WORLDWIDE FOR THE TREATMENT OF EPILEPSY, AS A MOOD STABILISER AND FOR ITS PAIN-RELIEVING PROPERTIES. IN ADDITION TO BIRTH DEFECTS, FVS IS ASSOCIATED WITH AN INCREASED RISK OF AUTISM SPECTRUM DISORDER (ASD), WHICH IS CHARACTERISED BY ABNORMAL BEHAVIOURS. VALPROATE PERTURBS MULTIPLE BIOCHEMICAL PATHWAYS AND ALTERS GENE EXPRESSION THROUGH ITS INHIBITION OF HISTONE DEACETYLASES. WHICH, IF ANY, OF THESE MECHANISMS IS RELEVANT TO THE GENESIS OF ITS BEHAVIOURAL SIDE EFFECTS IS UNCLEAR. NEUROANATOMICAL CHANGES ASSOCIATED WITH FVS HAVE BEEN REPORTED AND, AMONG THESE, ALTERED SEROTONERGIC NEURONAL DIFFERENTIATION IS A CONSISTENT FINDING. ALTERED SEROTONIN HOMEOSTASIS IS ALSO ASSOCIATED WITH AUTISM. HERE WE HAVE USED A CHEMICAL-GENETICS APPROACH TO INVESTIGATE THE UNDERLYING MOLECULAR DEFECT IN A ZEBRAFISH FVS MODEL. VALPROATE CAUSES THE SELECTIVE FAILURE OF ZEBRAFISH CENTRAL SEROTONIN EXPRESSION. IT DOES SO BY DOWNREGULATING THE PRONEURAL GENE ASCL1B, AN ORTHOLOG OF MAMMALIAN ASCL1, WHICH IS A KNOWN DETERMINANT OF SEROTONERGIC IDENTITY IN THE MAMMALIAN BRAINSTEM. ASCL1B IS SUFFICIENT TO RESCUE SEROTONIN EXPRESSION IN VALPROATE-TREATED EMBRYOS. CHEMICAL AND GENETIC BLOCKADE OF THE HISTONE DEACETYLASE HDAC1 DOWNREGULATES ASCL1B, CONSISTENT WITH THE HDAC1-MEDIATED SILENCING OF ASCL1B EXPRESSION BY VALPROATE. MOREOVER, TONIC NOTCH SIGNALLING IS CRUCIAL FOR ASCL1B REPRESSION BY VALPROATE. CONCOMITANT BLOCKADE OF NOTCH SIGNALLING RESTORES ASCL1B EXPRESSION AND SEROTONIN EXPRESSION IN BOTH VALPROATE-EXPOSED AND HDAC1 MUTANT EMBRYOS. TOGETHER, THESE DATA PROVIDE A MOLECULAR EXPLANATION FOR SEROTONERGIC DEFECTS IN FVS AND HIGHLIGHT AN EPIGENETIC MECHANISM FOR GENOME-ENVIRONMENT INTERACTION IN DISEASE. 2014 9 195 20 ACF CHROMATIN-REMODELING COMPLEX MEDIATES STRESS-INDUCED DEPRESSIVE-LIKE BEHAVIOR. IMPROVED TREATMENT FOR MAJOR DEPRESSIVE DISORDER (MDD) REMAINS ELUSIVE BECAUSE OF THE LIMITED UNDERSTANDING OF ITS UNDERLYING BIOLOGICAL MECHANISMS. IT IS LIKELY THAT STRESS-INDUCED MALADAPTIVE TRANSCRIPTIONAL REGULATION IN LIMBIC NEURAL CIRCUITS CONTRIBUTES TO THE DEVELOPMENT OF MDD, POSSIBLY THROUGH EPIGENETIC FACTORS THAT REGULATE CHROMATIN STRUCTURE. WE ESTABLISH THAT PERSISTENT UPREGULATION OF THE ACF (ATP-UTILIZING CHROMATIN ASSEMBLY AND REMODELING FACTOR) ATP-DEPENDENT CHROMATIN-REMODELING COMPLEX, OCCURRING IN THE NUCLEUS ACCUMBENS OF STRESS-SUSCEPTIBLE MICE AND DEPRESSED HUMANS, IS NECESSARY FOR STRESS-INDUCED DEPRESSIVE-LIKE BEHAVIORS. WE FOUND THAT ALTERED ACF BINDING AFTER CHRONIC STRESS WAS CORRELATED WITH ALTERED NUCLEOSOME POSITIONING, PARTICULARLY AROUND THE TRANSCRIPTION START SITES OF AFFECTED GENES. THESE ALTERATIONS IN ACF BINDING AND NUCLEOSOME POSITIONING WERE ASSOCIATED WITH REPRESSED EXPRESSION OF GENES IMPLICATED IN SUSCEPTIBILITY TO STRESS. TOGETHER, OUR FINDINGS IDENTIFY THE ACF CHROMATIN-REMODELING COMPLEX AS A CRITICAL COMPONENT IN THE DEVELOPMENT OF SUSCEPTIBILITY TO DEPRESSION AND IN REGULATING STRESS-RELATED BEHAVIORS. 2015 10 5832 18 STRESS-INDUCED EPIGENETIC CHANGES IN HIPPOCAMPAL MKP-1 PROMOTE PERSISTENT DEPRESSIVE BEHAVIORS. CHRONIC STRESS INDUCES PERSISTENT DEPRESSIVE BEHAVIORS. STRESS-INDUCED TRANSCRIPTIONAL ALTERATION OVER THE HOMEOSTATIC RANGE IN STRESS HORMONE-SENSITIVE BRAIN REGIONS IS BELIEVED TO UNDERLIE LONG-LASTING DEPRESSIVE BEHAVIORS. HOWEVER, THE DETAILED MECHANISMS BY WHICH CHRONIC STRESS CAUSES THOSE ADAPTIVE CHANGES ARE NOT CLEARLY UNDERSTOOD. IN THE PRESENT STUDY, WE INVESTIGATED WHETHER EPIGENETIC CHANGES REGULATE STRESS-INDUCED DEPRESSIVE BEHAVIORS. WE FOUND THAT CHRONIC STRESS IN MICE DOWNREGULATES THE EPIGENETIC FACTORS HDAC2 AND SUV39H1 IN THE HIPPOCAMPUS. A SERIES OF FOLLOW-UP ANALYSES INCLUDING CHIP ASSAY AND SIRNA-MEDIATED FUNCTIONAL ANALYSES REVEAL THAT GLUCOCORTICOIDS RELEASED BY STRESS CUMULATIVELY INCREASE MKP-1 EXPRESSION IN THE HIPPOCAMPUS, AND INCREASED MKP-1 THEN DEBILITATES P-CREB AND PPARGAMMA, WHICH IN TURN SUPPRESS THE EPIGENETIC FACTORS HDAC2 AND SUV39H1. FURTHERMORE, HDAC2 AND SUV39H1 NORMALLY SUPPRESS THE TRANSCRIPTION OF THE MKP-1, AND THEREFORE THE REDUCED EXPRESSION OF HDAC2 AND SUV39H1 INCREASES MKP-1 EXPRESSION. ACCORDINGLY, REPEATED STRESS PROGRESSIVELY STRENGTHENS A VICIOUS CYCLE OF THE MKP-1 SIGNALING CASCADE THAT FACILITATES DEPRESSIVE BEHAVIORS. THESE RESULTS SUGGEST THAT THE HIPPOCAMPAL STRESS ADAPTATION SYSTEM COMPRISING HDAC2/SUV39H1-REGULATED MKP-1 SIGNALING NETWORK DETERMINES THE VULNERABILITY TO CHRONIC STRESS AND THE MAINTENANCE OF DEPRESSIVE BEHAVIORS. 2019 11 4861 21 ORGANIC ANION TRANSPORTER 1 IS AN HDAC4-REGULATED MEDIATOR OF NOCICEPTIVE HYPERSENSITIVITY IN MICE. PERSISTENT PAIN IS SUSTAINED BY MALADAPTIVE CHANGES IN GENE TRANSCRIPTION RESULTING IN ALTERED FUNCTION OF THE RELEVANT CIRCUITS; THERAPIES ARE STILL UNSATISFACTORY. THE EPIGENETIC MECHANISMS AND AFFECTED GENES LINKING NOCICEPTIVE ACTIVITY TO TRANSCRIPTIONAL CHANGES AND PATHOLOGICAL SENSITIVITY ARE UNCLEAR. HERE, WE FOUND THAT, AMONG SEVERAL HISTONE DEACETYLASES (HDACS), SYNAPTIC ACTIVITY SPECIFICALLY AFFECTS HDAC4 IN MURINE SPINAL CORD DORSAL HORN NEURONS. NOXIOUS STIMULI THAT INDUCE LONG-LASTING INFLAMMATORY HYPERSENSITIVITY CAUSE NUCLEAR EXPORT AND INACTIVATION OF HDAC4. THE DEVELOPMENT OF INFLAMMATION-ASSOCIATED MECHANICAL HYPERSENSITIVITY, BUT NEITHER ACUTE NOR BASAL SENSITIVITY, IS IMPAIRED BY THE EXPRESSION OF A CONSTITUTIVELY NUCLEAR LOCALIZED HDAC4 MUTANT. NEXT GENERATION RNA-SEQUENCING REVEALED AN HDAC4-REGULATED GENE PROGRAM COMPRISING MEDIATORS OF SENSITIZATION INCLUDING THE ORGANIC ANION TRANSPORTER OAT1, KNOWN FOR ITS RENAL TRANSPORT FUNCTION. USING PHARMACOLOGICAL AND MOLECULAR TOOLS TO MODULATE OAT1 ACTIVITY OR EXPRESSION, WE CAUSALLY LINK OAT1 TO PERSISTENT INFLAMMATORY HYPERSENSITIVITY IN MICE. THUS, HDAC4 IS A KEY EPIGENETIC REGULATOR THAT TRANSLATES NOCICEPTIVE ACTIVITY INTO SENSITIZATION BY REGULATING OAT1, WHICH IS A POTENTIAL TARGET FOR PAIN-RELIEVING THERAPIES. 2022 12 4499 27 MORPHINE WITHDRAWAL PRODUCES ERK-DEPENDENT AND ERK-INDEPENDENT EPIGENETIC MARKS IN NEURONS OF THE NUCLEUS ACCUMBENS AND LATERAL SEPTUM. EPIGENETIC CHANGES SUCH AS COVALENT MODIFICATIONS OF HISTONE PROTEINS REPRESENT COMPLEX MOLECULAR SIGNATURES THAT PROVIDE A CELLULAR MEMORY OF PREVIOUSLY EXPERIENCED STIMULI WITHOUT IRREVERSIBLE CHANGES OF THE GENETIC CODE. IN THIS STUDY WE SHOW THAT NEW GENE EXPRESSION INDUCED IN VIVO BY MORPHINE WITHDRAWAL OCCURS WITH CONCOMITANT EPIGENETIC MODIFICATIONS IN BRAIN REGIONS CRITICALLY INVOLVED IN DRUG-DEPENDENT BEHAVIORS. WE FOUND THAT NALOXONE-PRECIPITATED WITHDRAWAL, BUT NOT CHRONIC MORPHINE ADMINISTRATION, CAUSED A STRONG INDUCTION OF PHOSPHO-HISTONE H3 IMMUNOREACTIVITY IN THE NUCLEUS ACCUMBENS (NAC) SHELL/CORE AND IN THE LATERAL SEPTUM (LS), A CHANGE THAT WAS ACCOMPANIED BY AUGMENTED H3 ACETYLATION (LYS14) IN NEURONS OF THE NAC SHELL. MORPHINE WITHDRAWAL INDUCED THE PHOSPHORYLATION OF THE EPIGENETIC FACTOR METHYL-CPG-BINDING PROTEIN 2 (MECP2) IN SER421 BOTH IN THE LS AND THE NAC SHELL. THESE EPIGENETIC CHANGES WERE ACCOMPANIED BY THE ACTIVATION OF MEMBERS OF THE ERK PATHWAY AS WELL AS INCREASED EXPRESSION OF THE IMMEDIATE EARLY GENES (IEG) C-FOS AND ACTIVITY-REGULATED CYTOSKELETON-ASSOCIATED PROTEIN (ARC/ARG3.1). USING A PHARMACOLOGICAL APPROACH, WE FOUND THAT H3 PHOSPHORYLATION AND IEG EXPRESSION WERE PARTIALLY DEPENDENT ON ERK ACTIVATION, WHILE MECP2 PHOSPHORYLATION WAS FULLY ERK-INDEPENDENT. THESE FINDINGS PROVIDE NEW IMPORTANT INFORMATION ON THE ROLE OF THE ERK PATHWAY IN THE REGULATION OF EPIGENETIC MARKS AND GENE EXPRESSION THAT MAY CONCUR TO REGULATE IN VIVO THE CELLULAR CHANGES UNDERLYING THE ONSET OF THE OPIOID WITHDRAWAL SYNDROME. 2013 13 1182 35 CONVERGING AND DIFFERENTIAL BRAIN PHOSPHOLIPID DYSREGULATION IN THE PATHOGENESIS OF REPETITIVE MILD TRAUMATIC BRAIN INJURY AND ALZHEIMER'S DISEASE. REPETITIVE MILD TRAUMATIC BRAIN INJURY (RMTBI) IS A MAJOR EPIGENETIC RISK FACTOR FOR ALZHEIMER'S DISEASE (AD). THE PRECISE NATURE OF HOW RMTBI LEADS TO OR PRECIPITATES AD PATHOLOGY IS CURRENTLY UNKNOWN. NUMEROUS NEUROLOGICAL CONDITIONS HAVE SHOWN AN IMPORTANT ROLE FOR DYSFUNCTIONAL PHOSPHOLIPID METABOLISM AS A DRIVING FACTOR FOR THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES. HOWEVER, THE PRECISE ROLE IN RMTBI AND AD REMAINS ELUSIVE. WE HYPOTHESIZED THAT A DETAILED PHOSPHOLIPID CHARACTERIZATION WOULD REVEAL PROFILES OF RESPONSE TO INJURY IN TBI THAT OVERLAP WITH AGE-DEPENDENT CHANGES IN AD AND THUS PROVIDE INSIGHTS INTO THE TBI-AD RELATIONSHIP. WE EMPLOYED A LIPIDOMIC APPROACH EXAMINING BRAIN PHOSPHOLIPID PROFILES FROM MOUSE MODELS OF RMTBI AND AD. CORTEX AND HIPPOCAMPAL TISSUE WERE COLLECTED AT 24 H, 3, 6, 9, AND 12 MONTHS POST-RMTBI, AND AT AGES REPRESENTING 'PRE', 'PERI' AND 'POST' ONSET OF AMYLOID PATHOLOGY (I.E., 3, 9, 15 MONTHS-OLD). TOTAL LEVELS OF PHOSPHATIDYLCHOLINE (PC), PHOSPHATIDYLETHANOLAMINE (PE), LYSOPE, AND PHOSPHATIDYLINOSITOL (PI), INCLUDING THEIR MONOUNSATURATED, POLYUNSATURATED AND SATURATED FATTY ACID (FA) CONTAINING SPECIES WERE SIGNIFICANTLY INCREASED AT ACUTE AND/OR CHRONIC TIME POINTS POST-INJURY IN BOTH BRAIN REGIONS. HOWEVER, LEVELS OF MOST PHOSPHOLIPID SPECIES IN PS1/APP MICE WERE NOMINAL IN THE HIPPOCAMPUS, WHILE IN THE CORTEX, LEVELS WERE SIGNIFICANTLY DECREASED AT AGES POST-ONSET OF AMYLOID PATHOLOGY. SPHINGOMYELIN AND LYSOPC LEVELS SHOWED COINCIDENTAL TRENDS IN OUR RMTBI AND AD MODELS WITHIN THE HIPPOCAMPUS, AN INCREASE AT ACUTE AND/OR CHRONIC TIME POINTS EXAMINED. THE RATIO OF ARACHIDONIC ACID (OMEGA-6 FA) TO DOCOSAHEXAENOIC ACID (OMEGA-3 FA)-CONTAINING PE SPECIES WAS INCREASED AT EARLY TIME POINTS IN THE HIPPOCAMPUS OF INJURED VERSUS SHAM MICE, AND IN PS1/APP MICE THERE WAS A COINCIDENTAL INCREASE COMPARED TO WILD TYPE LITTERMATES AT ALL TIME POINTS. THIS STUDY DEMONSTRATES SOME OVERLAPPING AND DIVERSE PHOSPHOLIPID PROFILES IN RMTBI AND AD MODELS. FUTURE STUDIES ARE REQUIRED TO CORROBORATE OUR FINDINGS IN HUMAN POST-MORTEM TISSUE. INVESTIGATION OF SECONDARY MECHANISMS TRIGGERED BY ABERRANT DOWNSTREAM ALTERATIONS IN BIOACTIVE METABOLITES OF THESE PHOSPHOLIPIDS, AND THEIR MODULATION AT THE APPROPRIATE TIME-WINDOWS OF OPPORTUNITY COULD HELP FACILITATE DEVELOPMENT OF NOVEL THERAPEUTIC STRATEGIES TO AMELIORATE THE NEURODEGENERATIVE CONSEQUENCES OF RMTBI OR THE POTENTIAL TRIGGERING OF AD PATHOGENESIS BY RMTBI. 2019 14 3002 19 GENETIC, EPIGENETIC AND POSTTRANSCRIPTIONAL MECHANISMS FOR TREATMENT OF MAJOR DEPRESSION: THE 5-HT1A RECEPTOR GENE AS A PARADIGM. MAJOR DEPRESSION AND ANXIETY ARE HIGHLY PREVALENT AND INVOLVE CHRONIC DYSREGULATION OF SEROTONIN, BUT THEY REMAIN POORLY UNDERSTOOD. HERE, WE REVIEW NOVEL TRANSCRIPTIONAL (GENETIC, EPIGENETIC) AND POSTTRANSCRIPTIONAL (MICRORNA, ALTERNATIVE SPLICING) MECHANISMS IMPLICATED IN MENTAL ILLNESS, FOCUSING ON A KEY SEROTONIN-RELATED REGULATOR, THE SEROTONIN 1A (5-HT1A) RECEPTOR. FUNCTIONAL SINGLE-NUCLEOTIDE POLYMORPHISMS AND STRESS-INDUCED DNA METHYLATION OF THE 5-HT1A PROMOTER CONVERGE TO DIFFERENTIALLY ALTER PRE- AND POSTSYNAPTIC 5-HT1A RECEPTOR EXPRESSION ASSOCIATED WITH MAJOR DEPRESSION AND REDUCED THERAPEUTIC RESPONSE TO SEROTONERGIC ANTIDEPRESSANTS. MAJOR DEPRESSION IS ALSO ASSOCIATED WITH ALTERED LEVELS OF SPLICE FACTORS AND MICRORNA, POSTTRANSCRIPTIONAL MECHANISMS THAT REGULATE RNA STABILITY. THE HUMAN 5-HT1A 3'-UNTRANSLATED REGION IS ALTERNATIVELY SPLICED, REMOVING MICRORNA SITES AND INCREASING 5-HT1A EXPRESSION, WHICH IS REDUCED IN MAJOR DEPRESSION AND MAY BE GENOTYPE-DEPENDENT. THUS, THE 5-HT1A RECEPTOR GENE ILLUSTRATES THE CONVERGENCE OF GENETIC, EPIGENETIC AND POSTTRANSCRIPTIONAL MECHANISMS IN GENE EXPRESSION, NEURODEVELOPMENT AND NEUROPLASTICITY, AND MAJOR DEPRESSION. UNDERSTANDING GENE REGULATORY MECHANISMS COULD ENHANCE THE DETECTION, CATEGORIZATION AND PERSONALIZED TREATMENT OF MAJOR DEPRESSION. 2019 15 5503 24 RGS9-2--CONTROLLED ADAPTATIONS IN THE STRIATUM DETERMINE THE ONSET OF ACTION AND EFFICACY OF ANTIDEPRESSANTS IN NEUROPATHIC PAIN STATES. THE STRIATAL PROTEIN REGULATOR OF G-PROTEIN SIGNALING 9-2 (RGS9-2) PLAYS A KEY MODULATORY ROLE IN OPIOID, MONOAMINE, AND OTHER G-PROTEIN-COUPLED RECEPTOR RESPONSES. HERE, WE USE THE MURINE SPARED-NERVE INJURY MODEL OF NEUROPATHIC PAIN TO INVESTIGATE THE MECHANISM BY WHICH RGS9-2 IN THE NUCLEUS ACCUMBENS (NAC), A BRAIN REGION INVOLVED IN MOOD, REWARD, AND MOTIVATION, MODULATES THE ACTIONS OF TRICYCLIC ANTIDEPRESSANTS (TCAS). PREVENTION OF RGS9-2 ACTION IN THE NAC INCREASES THE EFFICACY OF THE TCA DESIPRAMINE AND DRAMATICALLY ACCELERATES ITS ONSET OF ACTION. BY CONTROLLING THE ACTIVATION OF EFFECTOR MOLECULES BY G PROTEIN ALPHA AND BETAGAMMA SUBUNITS, RGS9-2 AFFECTS SEVERAL PROTEIN INTERACTIONS, PHOSPHOPROTEIN LEVELS, AND THE FUNCTION OF THE EPIGENETIC MODIFIER HISTONE DEACETYLASE 5, WHICH ARE IMPORTANT FOR TCA RESPONSIVENESS. FURTHERMORE, INFORMATION FROM RNA-SEQUENCING ANALYSIS REVEALS THAT RGS9-2 IN THE NAC AFFECTS THE EXPRESSION OF MANY GENES KNOWN TO BE INVOLVED IN NOCICEPTION, ANALGESIA, AND ANTIDEPRESSANT DRUG ACTIONS. OUR FINDINGS PROVIDE NOVEL INFORMATION ON NAC-SPECIFIC CELLULAR MECHANISMS THAT MEDIATE THE ACTIONS OF TCAS IN NEUROPATHIC PAIN STATES. 2015 16 237 30 ADENOSINE AUGMENTATION EVOKED BY AN ENT1 INHIBITOR IMPROVES MEMORY IMPAIRMENT AND NEURONAL PLASTICITY IN THE APP/PS1 MOUSE MODEL OF ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS A NEURODEGENERATIVE DISORDER CHARACTERIZED BY COGNITIVE IMPAIRMENT AND SYNAPTIC DYSFUNCTION. ADENOSINE IS AN IMPORTANT HOMEOSTATIC MODULATOR THAT CONTROLS THE BIOENERGETIC NETWORK IN THE BRAIN THROUGH REGULATING RECEPTOR-EVOKED SIGNALING PATHWAYS, BIOENERGETIC MACHINERIES, AND EPIGENETIC-MEDIATED GENE REGULATION. EQUILIBRATIVE NUCLEOSIDE TRANSPORTER 1 (ENT1) IS A MAJOR ADENOSINE TRANSPORTER THAT RECYCLES ADENOSINE FROM THE EXTRACELLULAR SPACE. IN THE PRESENT STUDY, WE REPORT THAT A SMALL ADENOSINE ANALOGUE (DESIGNATED J4) THAT INHIBITED ENT1 PREVENTED THE DECLINE IN SPATIAL MEMORY IN AN AD MOUSE MODEL (APP/PS1). ELECTROPHYSIOLOGICAL AND BIOCHEMICAL ANALYSES FURTHER DEMONSTRATED THAT CHRONIC TREATMENT WITH J4 NORMALIZED THE IMPAIRED BASAL SYNAPTIC TRANSMISSION AND LONG-TERM POTENTIATION (LTP) AT SCHAFFER COLLATERAL SYNAPSES AS WELL AS THE ABERRANT EXPRESSION OF SYNAPTIC PROTEINS (E.G., NR2A AND NR2B), ABNORMAL NEURONAL PLASTICITY-RELATED SIGNALING PATHWAYS (E.G., PKA AND GSK3BETA), AND DETRIMENTAL ELEVATION IN ASTROCYTIC A(2A)R EXPRESSION IN THE HIPPOCAMPUS AND CORTEX OF APP/PS1 MICE. IN CONCLUSION, OUR FINDINGS SUGGEST THAT MODULATION OF ADENOSINE HOMEOSTASIS BY J4 IS BENEFICIAL IN A MOUSE MODEL OF AD. OUR STUDY PROVIDES A POTENTIAL THERAPEUTIC STRATEGY TO DELAY THE PROGRESSION OF AD. 2018 17 5065 33 PHOTOPERIOD-INDUCED NEUROTRANSMITTER PLASTICITY DECLINES WITH AGING: AN EPIGENETIC REGULATION? NEUROPLASTICITY HAS CLASSICALLY BEEN UNDERSTOOD TO ARISE THROUGH CHANGES IN SYNAPTIC STRENGTH OR SYNAPTIC CONNECTIVITY. A NEWLY DISCOVERED FORM OF NEUROPLASTICITY, NEUROTRANSMITTER SWITCHING, INVOLVES CHANGES IN NEUROTRANSMITTER IDENTITY. CHRONIC EXPOSURE TO DIFFERENT PHOTOPERIODS ALTERS THE NUMBER OF DOPAMINE (TYROSINE HYDROXYLASE, TH+) AND SOMATOSTATIN (SST+) NEURONS IN THE PARAVENTRICULAR NUCLEUS (PAVN) OF THE HYPOTHALAMUS OF ADULT RATS AND RESULTS IN DISCRETE BEHAVIORAL CHANGES. HERE, WE INVESTIGATE WHETHER PHOTOPERIOD-INDUCED NEUROTRANSMITTER SWITCHING PERSISTS DURING AGING AND WHETHER EPIGENETIC MECHANISMS OF HISTONE ACETYLATION AND DNA METHYLATION MAY CONTRIBUTE TO THIS NEUROTRANSMITTER PLASTICITY. WE SHOW THAT THIS PLASTICITY IN RATS IS ROBUST AT 1 AND AT 3 MONTHS BUT REDUCED IN TH+ NEURONS AT 12 MONTHS AND COMPLETELY ABOLISHED IN BOTH TH+ AND SST+ NEURONS BY 18 MONTHS. DE NOVO EXPRESSION OF DNMT3A CATALYZING DNA METHYLATION AND ANTI-ACETYLH3 ASSESSING HISTONE 3 ACETYLATION WERE OBSERVED FOLLOWING SHORT-DAY PHOTOPERIOD EXPOSURE IN BOTH TH+ AND SST+ NEURONS AT 1 AND 3 MONTHS WHILE AN OVERALL INCREASE IN DNMT3A IN SST+ NEURONS PARALLELED NEUROPLASTICITY REDUCTION AT 12 AND 18 MONTHS. HISTONE ACETYLATION INCREASED IN TH+ NEURONS AND DECREASED IN SST+ NEURONS FOLLOWING SHORT-DAY EXPOSURE AT 3 MONTHS WHILE THE TOTAL NUMBER OF ANTI-ACETYLH3+ PAVN NEURONS REMAINED CONSTANT. RECIPROCAL HISTONE ACETYLATION IN TH+ AND SST+ NEURONS INDICATES THE IMPORTANCE OF STUDYING EPIGENETIC REGULATION AT THE CIRCUIT LEVEL FOR IDENTIFIED CELL PHENOTYPES. THE FINDINGS MAY BE USEFUL FOR DEVELOPING APPROACHES FOR NONINVASIVE TREATMENT OF DISORDERS CHARACTERIZED BY NEUROTRANSMITTER DYSFUNCTION. 2020 18 3122 37 GESTATIONAL VALPROIC ACID EXPOSURE INDUCES EPIGENETIC MODIFICATIONS IN MURINE DECIDUA. INTRODUCTION: VALPROIC ACID (VPA), A WIDELY PRESCRIBED ANTIEPILEPTIC DRUG AND AN EFFECTIVE TREATMENT FOR BIPOLAR DISORDER AND NEUROPATHIC PAIN, RESULTS IN MULTIPLE DEVELOPMENTAL DEFECTS FOLLOWING IN UTERO EXPOSURE. UTERINE DECIDUA PROVIDES NUTRITIONAL AND PHYSICAL SUPPORT DURING IMPLANTATION AND EARLY EMBRYONIC DEVELOPMENT. PERTURBATIONS IN THE MOLECULAR MECHANISMS WITHIN DECIDUAL TISSUE DURING EARLY PREGNANCY MIGHT AFFECT EARLY EMBRYONIC GROWTH, RESULT IN EARLY PREGNANCY LOSS OR CAUSE COMPLICATIONS IN THE LATER GESTATIONAL STAGE. VPA IS A KNOWN HISTONE DEACETYLASE INHIBITOR AND EPIGENETIC CHANGES SUCH AS HISTONE HYPERACETYLATION AND METHYLATION HAVE BEEN PROPOSED AS A MECHANISM OF VPA-INDUCED TERATOGENESIS. METHODS: THIS STUDY INVESTIGATED THE EFFECTS OF IN UTERO VPA EXPOSURE ON HISTONE MODIFICATIONS IN MURINE DECIDUAL TISSUE. PREGNANT CD-1 MICE WERE EXPOSED TO 400 MG/KG VPA OR SALINE ON GD9 VIA SUBCUTANEOUS INJECTION. DECIDUAL TISSUE FROM EACH GESTATIONAL SAC WAS HARVESTED AT 1, 3 AND 6 H FOLLOWING EXPOSURE. LEVELS OF ACETYLATED HISTONES H3, H4 AND H3K56, AS WELL AS METHYLATED HISTONES H3K9 AND H3K27 WERE ACID EXTRACTED AND ASSESSED BY WESTERN BLOTTING FOLLOWED BY ACID HISTONE EXTRACTION. RESULTS: VPA EXPOSURE INDUCED A SIGNIFICANT INCREASE (P < 0.05) IN THE LEVELS OF ACETYLATED H3 AT 1, 3 H; ACETYLATED H4 AT 1, 3 AND 6 H AND TRIMETHYLATED H3K9 AT 6 H. IN CONTRAST, NO SIGNIFICANT PERTURBATIONS WERE NOTED IN THE LEVELS OF MONOMETHYLATED H3K9, TRIMETHYLATED H3K27 AND ACETYLATED H3K56. DISCUSSION: THE RESULTS FROM THIS STUDY SUGGEST THAT VPA-INDUCED DECIDUAL HISTONE MODIFICATIONS MIGHT PLAY AN IMPORTANT ROLE AS A MECHANISM OF VPA-INDUCED TERATOGENESIS DURING EARLY EMBRYONIC GROWTH. 2021 19 856 24 CHROMATIN ACCESSIBILITY MAPPING OF THE STRIATUM IDENTIFIES TYROSINE KINASE FYN AS A THERAPEUTIC TARGET FOR HEROIN USE DISORDER. THE CURRENT OPIOID EPIDEMIC NECESSITATES A BETTER UNDERSTANDING OF HUMAN ADDICTION NEUROBIOLOGY TO DEVELOP EFFICACIOUS TREATMENT APPROACHES. HERE, WE PERFORM GENOME-WIDE ASSESSMENT OF CHROMATIN ACCESSIBILITY OF THE HUMAN STRIATUM IN HEROIN USERS AND MATCHED CONTROLS. OUR STUDY REVEALS DISTINCT NEURONAL AND NON-NEURONAL EPIGENETIC SIGNATURES, AND IDENTIFIES A LOCUS IN THE PROXIMITY OF THE GENE ENCODING TYROSINE KINASE FYN AS THE MOST AFFECTED REGION IN NEURONS. FYN EXPRESSION, KINASE ACTIVITY AND THE PHOSPHORYLATION OF ITS TARGET TAU ARE INCREASED BY HEROIN USE IN THE POST-MORTEM HUMAN STRIATUM, AS WELL AS IN RATS TRAINED TO SELF-ADMINISTER HEROIN AND PRIMARY STRIATAL NEURONS TREATED WITH CHRONIC MORPHINE IN VITRO. PHARMACOLOGICAL OR GENETIC MANIPULATION OF FYN ACTIVITY SIGNIFICANTLY ATTENUATES HEROIN SELF-ADMINISTRATION AND RESPONDING FOR DRUG-PAIRED CUES IN RODENTS. OUR FINDINGS SUGGEST THAT STRIATAL FYN IS AN IMPORTANT DRIVER OF HEROIN-RELATED NEURODEGENERATIVE-LIKE PATHOLOGY AND DRUG-TAKING BEHAVIOR, MAKING FYN A PROMISING THERAPEUTIC TARGET FOR HEROIN USE DISORDER. 2020 20 984 26 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022