1 4982 123 PATHOPHYSIOLOGY OF THE BLOOD-BRAIN BARRIER: ANIMAL MODELS AND METHODS. THE SPECIALIZED CEREBRAL MICROVASCULAR ENDOTHELIUM INTERACTS WITH THE CELLULAR MILIEU OF THE BRAIN AND EXTRACELLULAR MATRIX TO FORM A NEUROVASCULAR UNIT, ONE ASPECT OF WHICH IS A REGULATED INTERFACE BETWEEN THE BLOOD AND CENTRAL NERVOUS SYSTEM (CNS). THE CONCEPT OF THIS BLOOD-BRAIN BARRIER (BBB) AS A DYNAMICALLY REGULATED SYSTEM RATHER THAN A STATIC BARRIER HAS WIDE-RANGING IMPLICATIONS FOR PATHOPHYSIOLOGY OF THE CNS. WHILE IN VITRO MODELS OF THE BBB ARE USEFUL FOR SCREENING DRUGS TARGETED TO THE CNS AND INDISPENSABLE FOR STUDIES OF CEREBRAL ENDOTHELIAL CELL BIOLOGY, THE COMPLEX INTERACTIONS OF THE NEUROVASCULAR UNIT MAKE ANIMAL-BASED MODELS AND METHODS ESSENTIAL TOOLS FOR UNDERSTANDING THE PATHOPHYSIOLOGY OF THE BBB. BBB DYSFUNCTION IS A COMPLICATION OF NEURODEGENERATIVE DISEASE AND BRAIN INJURY. STUDIES ON ANIMAL MODELS HAVE SHOWN THAT DISEASES OF THE PERIPHERY, SUCH AS DIABETES AND INFLAMMATORY PAIN, HAVE DELETERIOUS EFFECTS ON THE BBB WHICH MAY CONTRIBUTE TO NEUROLOGICAL COMPLICATIONS ASSOCIATED WITH THESE CONDITIONS. FURTHERMORE, GENETIC AND/OR EPIGENETIC ABNORMALITIES IN CONSTITUENTS OF THE BBB MAY BE SIGNIFICANT CONTRIBUTING FACTORS IN DISEASE ETIOLOGY. RESEARCH THAT APPROACHES THE BBB AS A DYNAMIC SYSTEM INTEGRATED WITH BOTH THE CNS AND THE PERIPHERY IS THEREFORE CRITICAL TO UNDERSTANDING AND TREATING DISEASES OF THE CNS. HEREIN, WE REVIEW VARIOUS METHODOLOGICAL APPROACHES USED TO STUDY BBB FUNCTION IN THE CONTEXT OF DISEASE. THESE INCLUDE MEASUREMENT OF TRANSPORT BETWEEN BLOOD AND BRAIN, IMAGING-BASED TECHNOLOGIES, AND GENOMIC/PROTEOMIC APPROACHES. 2008 2 3120 38 GESTATIONAL HYPOXIA AND BLOOD-BRAIN BARRIER PERMEABILITY: EARLY ORIGINS OF CEREBROVASCULAR DYSFUNCTION INDUCED BY EPIGENETIC MECHANISMS. FETAL CHRONIC HYPOXIA LEADS TO INTRAUTERINE GROWTH RESTRICTION (IUGR), WHICH IS LIKELY TO REDUCE OXYGEN DELIVERY TO THE BRAIN AND INDUCE LONG-TERM NEUROLOGICAL IMPAIRMENTS. THESE INDICATE A MODULATORY ROLE FOR OXYGEN IN CEREBROVASCULAR DEVELOPMENT. DURING INTRAUTERINE HYPOXIA, THE FETAL CIRCULATION SUFFERS MARKED ADAPTATIONS IN THE FETAL CARDIAC OUTPUT TO MAINTAIN OXYGEN AND NUTRIENT DELIVERY TO VITAL ORGANS, KNOWN AS THE "BRAIN-SPARING PHENOTYPE." THIS IS A WELL-CHARACTERIZED RESPONSE; HOWEVER, LITTLE IS KNOWN ABOUT THE POSTNATAL COURSE AND OUTCOMES OF THIS FETAL CEREBROVASCULAR ADAPTATION. IN ADDITION, SEVERAL NEURODEVELOPMENTAL DISORDERS HAVE THEIR ORIGINS DURING GESTATION. STILL, FEW STUDIES HAVE FOCUSED ON HOW INTRAUTERINE FETAL HYPOXIA MODULATES THE NORMAL BRAIN DEVELOPMENT OF THE BLOOD-BRAIN BARRIER (BBB) IN THE IUGR NEONATE. THE BBB IS A CELLULAR STRUCTURE FORMED BY THE NEUROVASCULAR UNIT (NVU) AND IS ORGANIZED BY A MONOLAYER OF ENDOTHELIAL AND MURAL CELLS. THE BBB REGULATES THE ENTRY OF PLASMA CELLS AND MOLECULES FROM THE SYSTEMIC CIRCULATION TO THE BRAIN. A HIGHLY SELECTIVE PERMEABILITY SYSTEM ACHIEVES THIS THROUGH INTEGRAL MEMBRANE PROTEINS IN BRAIN ENDOTHELIAL CELLS. BBB BREAKDOWN AND DYSFUNCTION IN CEREBROVASCULAR DISEASES LEAD TO LEAKAGE OF BLOOD COMPONENTS INTO THE BRAIN PARENCHYMA, CONTRIBUTING TO NEUROLOGICAL DEFICITS. THE FETAL BRAIN CIRCULATION IS PARTICULARLY SUSCEPTIBLE IN IUGR AND IS PROPOSED TO BE ONE OF THE MAIN PATHOLOGICAL PROCESSES DERIVING BBB DISRUPTION. IN THE LAST DECADE, SEVERAL EPIGENETIC MECHANISMS ACTIVATED BY IU HYPOXIA HAVE BEEN PROPOSED TO REGULATE THE POSTNATAL BBB PERMEABILITY. HOWEVER, FEW MECHANISTIC STUDIES ABOUT THIS TOPIC ARE AVAILABLE, AND LITTLE EVIDENCE SHOWS CONTROVERSY. THEREFORE, IN THIS MINI-REVIEW, WE ANALYZE THE BBB PERMEABILITY-ASSOCIATED EPIGENETIC MECHANISMS IN THE BRAIN EXPOSED TO CHRONIC INTRAUTERINE HYPOXIA. 2021 3 83 33 A NOVEL EPIGENETIC MARKER, TEN-ELEVEN TRANSLOCATION FAMILY MEMBER 2 (TET2), IS IDENTIFIED IN THE INTRACTABLE EPILEPTIC BRAIN AND REGULATES ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) IN THE BLOOD-BRAIN BARRIER. DRUG-RESISTANT EPILEPSY (DRE) IS A CHRONIC CONDITION DERIVED FROM SPONTANEOUS CHANGES AND REGULATORY EFFECTS IN THE EPILEPTIC BRAIN. AS DEMETHYLATION FACTORS, TEN-ELEVEN TRANSLOCATION (TET) FAMILY MEMBERS HAVE BECOME A FOCUS IN RECENT STUDIES OF NEUROLOGICAL DISORDERS. HERE, WE QUANTIFIED AND LOCALIZED TET1, TET2 AND 5-HYDROXYMETHYLCYTOSINE (5-HMC) IN THE TEMPORAL LOBE CORTEX OF DRE PATIENTS (N = 27) AND TRAUMATIC BRAIN HEMORRHAGE CONTROLS (N = 10) BY IMMUNOCHEMICAL STAINING. TET2 AND ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) EXPRESSION PATTERNS WERE DETERMINED IN THE ISOLATED BRAIN CAPILLARIES OF DRE PATIENTS. TET2 EXPRESSION WAS SIGNIFICANTLY INCREASED IN THE TEMPORAL CORTICAL TISSUE OF DRE PATIENTS WITH OR WITHOUT HIPPOCAMPAL SCLEROSIS (HS) COMPARED TO CONTROL PATIENTS, WHILE TET1 AND 5-HMC SHOWED NO DIFFERENCES IN EXPRESSION. WE ALSO FOUND THAT A PARTICULARLY STRONG EXPRESSION OF TET2 IN THE VASCULAR TISSUE OF DRE PATIENTS. ABCB1 AND TET2 HAVE EVIDENTLY HIGHER EXPRESSION IN THE VASCULAR ENDOTHELIUM FROM THE NEOCORTEX OF DRE PATIENTS. IN BLOOD-BRAIN BARRIER (BBB) MODEL, TET2 DEPLETION CAN CAUSE ATTENUATED EXPRESSION AND FUNCTION OF ABCB1. DATA FROM A COHORT STUDY AND EXPERIMENTS IN A BBB MODEL SUGGEST THAT TET2 HAS A SPECIFIC REGULATORY EFFECT ON ABCB1, WHICH MAY SERVE AS A POTENTIAL MECHANISM AND TARGET IN DRE. 2022 4 2710 25 EXERCISE MITIGATES ALCOHOL INDUCED ENDOPLASMIC RETICULUM STRESS MEDIATED COGNITIVE IMPAIRMENT THROUGH ATF6-HERP SIGNALING. CHRONIC ETHANOL/ALCOHOL (AL) DOSING CAUSES AN ELEVATION IN HOMOCYSTEINE (HCY) LEVELS, WHICH LEADS TO THE CONDITION KNOWN AS HYPERHOMOCYSTEINEMIA (HHCY). HHCY ENHANCES OXIDATIVE STRESS AND BLOOD-BRAIN-BARRIER (BBB) DISRUPTION THROUGH MODULATION OF ENDOPLASMIC RETICULUM (ER) STRESS; IN PART BY EPIGENETIC ALTERNATION, LEADING TO COGNITIVE IMPAIRMENT. CLINICIANS HAVE RECOMMENDED EXERCISE AS A THERAPY; HOWEVER, ITS PROTECTIVE EFFECT ON COGNITIVE FUNCTIONS HAS NOT BEEN FULLY EXPLORED. THE PRESENT STUDY WAS DESIGNED TO OBSERVE THE PROTECTIVE EFFECTS OF EXERCISE (EX) AGAINST ALCOHOL-INDUCED EPIGENETIC AND MOLECULAR ALTERATIONS LEADING TO CEREBROVASCULAR DYSFUNCTION. WILD-TYPE MICE WERE SUBJECTED TO AL ADMINISTRATION (1.5 G/KG-BW) AND SUBSEQUENT TREADMILL EX FOR 12 WEEKS (5 DAY/WEEK@7-11 M/MIN). AL AFFECTED MOUSE BRAIN THROUGH INCREASES IN OXIDATIVE AND ER STRESS MARKERS, SAHH AND DNMTS ALTERNATION, WHILE DECREASES IN CBS, CSE, MTHFR, TIGHT-JUNCTION PROTEINS AND CELLULAR H(2)S LEVELS. MECHANISTIC STUDY REVEALED THAT AL INCREASED EPIGENETIC DNA HYPOMETHYLATION OF HERP PROMOTER. BBB DYSFUNCTION AND COGNITIVE IMPAIRMENT WERE OBSERVED IN THE AL TREATED MICE. AL MEDIATED TRANSCRIPTIONAL CHANGES WERE ABOLISHED BY ADMINISTRATION OF ER STRESS INHIBITOR DTT. IN CONCLUSION, EXERCISE RESTORED HCY AND H(2)S TO BASAL LEVELS WHILE AMELIORATING AL-INDUCED ER STRESS, DIMINISHING BBB DYSFUNCTION AND IMPROVING COGNITIVE FUNCTION VIA ATF6-HERP-SIGNALING. EX SHOWED ITS PROTECTIVE EFFICACY AGAINST AL-INDUCED NEUROTOXICITY. 2018 5 4338 30 MICROVASCULAR BARRIER PROTECTION BY MICRORNA-183 VIA FOXO1 REPRESSION: A PATHWAY DISTURBED IN NEUROPATHY AND COMPLEX REGIONAL PAIN SYNDROME. BLOOD NERVE BARRIER DISRUPTION AND EDEMA ARE COMMON IN NEUROPATHIC PAIN AS WELL AS IN COMPLEX REGIONAL PAIN SYNDROME (CRPS). MICRORNAS (MIRNA) ARE EPIGENETIC MULTITARGET SWITCHES CONTROLLING NEURONAL AND NON-NEURONAL CELLS IN PAIN. THE MIR-183 COMPLEX ATTENUATES HYPEREXCITABILITY IN NOCICEPTORS, BUT ADDITIONAL NON-NEURONAL EFFECTS VIA TRANSCRIPTION FACTORS COULD CONTRIBUTE AS WELL. THIS STUDY EXPLORED EXOSOMAL MIR-183 IN CRPS AND MURINE NEUROPATHY, ITS EFFECT ON THE MICROVASCULAR BARRIER VIA TRANSCRIPTION FACTOR FOXO1 AND TIGHT JUNCTION PROTEIN CLAUDIN-5, AND ITS ANTIHYPERALGESIC POTENTIAL. SCIATIC MIR-183 DECREASED AFTER CCI. SUBSTITUTION WITH PERINEURAL MIR-183 MIMIC ATTENUATED MECHANICAL HYPERSENSITIVITY AND RESTORED BLOOD NERVE BARRIER FUNCTION. IN VITRO, SERUM FROM CCI MICE UND CRPS PATIENTS WEAKENED THE MICROVASCULAR BARRIER OF MURINE CEREBELLAR ENDOTHELIAL CELLS, INCREASED ACTIVE FOXO1 AND REDUCED CLAUDIN-5, CONCOMITANT WITH A LACK OF EXOSOMAL MIR-183 IN CRPS PATIENTS. CELLULAR STRESS ALSO COMPROMISED THE MICROVASCULAR BARRIER WHICH WAS RESCUED EITHER BY MIR-183 MIMIC VIA FOXO1 REPRESSION OR BY PRIOR SILENCING OF FOXO1. PERSPECTIVE: LOW MIR-183 LEADING TO BARRIER IMPAIRMENT VIA FOXO1 AND SUBSEQUENT CLAUDIN-5 SUPPRESSION IS A NEW ASPECT IN THE PATHOPHYSIOLOGY OF CRPS AND NEUROPATHIC PAIN. THIS PATHWAY MIGHT HELP UNTANGLE THE WIDE SYMPTOMATIC RANGE OF CRPS AND NURTURE FURTHER RESEARCH INTO MIRNA MIMICS OR FOXO1 INHIBITORS. 2022 6 6531 36 TRANSCRIPTIONAL REGULATION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) BY METHYL CPG BINDING PROTEIN 2 (MECP2): A NOVEL MECHANISM FOR RE-MYELINATION AND/OR MYELIN REPAIR INVOLVED IN THE TREATMENT OF MULTIPLE SCLEROSIS (MS). MULTIPLE SCLEROSIS (MS) IS A CHRONIC PROGRESSIVE, NEUROLOGICAL DISEASE CHARACTERIZED BY THE TARGETED IMMUNE SYSTEM-MEDIATED DESTRUCTION OF CENTRAL NERVOUS SYSTEM (CNS) MYELIN. AUTOREACTIVE CD4+ T HELPER CELLS HAVE A KEY ROLE IN ORCHESTRATING MS-INDUCED MYELIN DAMAGE. ONCE ACTIVATED, CIRCULATING TH1-CELLS SECRETE A VARIETY OF INFLAMMATORY CYTOKINES THAT FOSTER THE BREAKDOWN OF BLOOD-BRAIN BARRIER (BBB) EVENTUALLY INFILTRATING INTO THE CNS. INSIDE THE CNS, THEY BECOME REACTIVATED UPON EXPOSURE TO THE MYELIN STRUCTURAL PROTEINS AND CONTINUE TO PRODUCE INFLAMMATORY CYTOKINES SUCH AS TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) THAT LEADS TO DIRECT ACTIVATION OF ANTIBODIES AND MACROPHAGES THAT ARE INVOLVED IN THE PHAGOCYTOSIS OF MYELIN. PROLIFERATING OLIGODENDROCYTE PRECURSORS (OPS) MIGRATING TO THE LESION SITES ARE CAPABLE OF ACUTE REMYELINATION BUT UNABLE TO COMPLETELY REPAIR OR RESTORE THE IMMUNE SYSTEM-MEDIATED MYELIN DAMAGE. THIS RESULTS IN VARIOUS PERMANENT CLINICAL NEUROLOGICAL DISABILITIES SUCH AS COGNITIVE DYSFUNCTION, FATIGUE, BOWEL/BLADDER ABNORMALITIES, AND NEUROPATHIC PAIN. AT PRESENT, THERE IS NO CURE FOR MS. RECENT REMYELINATION AND/OR MYELIN REPAIR STRATEGIES HAVE FOCUSED ON THE ROLE OF THE NEUROTROPHIN BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) AND ITS UPSTREAM TRANSCRIPTIONAL REPRESSOR METHYL CPG BINDING PROTEIN (MECP2). RESEARCH IN THE FIELD OF EPIGENETIC THERAPEUTICS INVOLVING HISTONE DEACETYLASE (HDAC) INHIBITORS AND LYSINE ACETYL TRANSFERASE (KAT) INHIBITORS IS BEING EXPLORED TO REPRESS THE DETRIMENTAL EFFECTS OF MECP2. THIS REVIEW WILL ADDRESS THE ROLE OF MECP2 AND BDNF IN REMYELINATION AND/OR MYELIN REPAIR AND THE POTENTIAL OF HDAC AND KAT INHIBITORS AS NOVEL THERAPEUTIC INTERVENTIONS FOR MS. 2016 7 6108 22 THE ENRICHED ENVIRONMENT AMELIORATES CHRONIC UNPREDICTABLE MILD STRESS-INDUCED DEPRESSIVE-LIKE BEHAVIORS AND COGNITIVE IMPAIRMENT BY ACTIVATING THE SIRT1/MIR-134 SIGNALING PATHWAY IN HIPPOCAMPUS. BACKGROUND: CHRONIC UNPREDICTABLE MILD STRESS (CUMS) IS AN IMPORTANT RISK FACTOR FOR DEPRESSION AND COGNITIVE DEFICITS IN HUMANS. ENRICHED ENVIRONMENT (EE) SHOWED A BENEFICIAL EFFECT ON DEPRESSION AND COGNITION BY ENHANCING BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION AND SYNAPTIC PLASTICITY. HOWEVER, IT IS STILL NOT CLEARLY UNDERSTOOD WHETHER AN EPIGENETIC MECHANISM IS INVOLVED IN THE BDNF MODULATION AND SYNAPTIC PLASTICITY THAT OCCURS AFTER EE TREATMENT FOR THE DEPRESSIVE-LIKE BEHAVIORS AND COGNITIVE DEFICITS ELICITED BY CUMS. IN THIS STUDY, WE INVESTIGATED THE POSSIBLE MECHANISM OF THE NEUROPROTECTIVE EFFECT OF EE. METHODS: ALL RATS WERE EXPOSED TO THE 5-WEEK CUMS PROCEDURE EXCEPT THE CONTROL GROUP. AFTER CUMS PROCEDURE, SOME RATS WERE STEREOTAXICALLY INJECTED WITH SIRT1 PHARMACOLOGIC INHIBITOR EX527 OR SIRT1 KNOCKING DOWN LENTIVIRUS (SH-SIRT1) IN THE HIPPOCAMPUS FOLLOWED BY EE TREATMENT FOR 3 WEEKS. OTHER RATS WERE DIRECTLY SUBJECTED TO EE TREATMENT WITHOUT STEREOTAXIC INJECTION. BEHAVIORAL TESTS WERE USED TO APPRAISE DEPRESSION AND COGNITION AFTER EE TREATMENT. THEN EPIGENETIC MOLECULES, SYNAPTIC PROTEINS, DENDRITIC SPINE DENSITY AND BRANCHES, AND SYNAPTIC MORPHOLOGY OF THE DORSAL HIPPOCAMPUS WERE DETERMINED. RESULTS: WE FOUND THAT CUMS INDUCED DEPRESSIVE-LIKE BEHAVIORS INCLUDING DECREASED SUCROSE PREFERENCE RATIO, PROLONGED IMMOBILITY AND REDUCED LOCOMOTOR AND EXPLORATORY ACTIVITY; COGNITIVE DEFICITS INCLUDING SPATIAL LEARNING AND MEMORY IMPAIRMENT; REDUCED DENDRITIC SPINE DENSITY AND NUMBER OF BRANCHES; THINNED POSTSYNAPTIC DENSITY; DOWNREGULATED SIRT1/MICRORNA-134 PATHWAY, DECREASED BDNF AND SYNAPTIC PROTEINS INCLUDING SYNAPTOPHYSIN (SYN) AND POSTSYNAPTIC DENSITY PROTEIN 95 (PSD95) EXPRESSION IN THE HIPPOCAMPUS. HOWEVER, THE CUMS-INDUCED DEPRESSIVE-LIKE BEHAVIORS, COGNITIVE DEFICITS, DENDRITIC SPINE DENSITY AND BRANCH NUMBER REDUCTION, POSTSYNAPTIC DENSITY THINNING, SIRT1/MICRORNA-134 PATHWAY DOWNREGULATION, BDNF AND SYNAPTIC PROTEINS REDUCTION, INCLUDING SYNAPTOPHYSIN (SYN) AND POSTSYNAPTIC DENSITY PROTEIN 95 (PSD95), WERE REVERSED BY EE TREATMENT. HOWEVER, DEPRESSIVE-LIKE BEHAVIORS AND COGNITIVE DEFICITS WERE OBSERVED AGAIN IN RATS SUBJECTED TO STEREOTAXIC INJECTION WITH EX527 OR SH-SIRT1. FURTHERMORE, THIS STUDY ALSO FOUND THAT SIRT1/MICRORNA-134 REGULATES THE DOWNSTREAM MOLECULES BDNF, AND THE SYNAPTIC PROTEINS SYN AND PSD95 IN PRIMARY CULTURED HIPPOCAMPAL NEURONS. CONCLUSIONS: THIS STUDY PROVIDES EVIDENCE FOR THE NEUROPROTECTIVE ROLE OF EE ON DEPRESSION AND COGNITIVE DEFICITS BY ACTIVATING THE SIRT1/MICRORNA-134 PATHWAY, WHICH ACCOUNTS FOR THE REGULATION OF SYNAPTIC PROTEINS, INCLUDING BDNF, PSD95 AND SYN, DENDRITIC REMODELING AND ULTRASTRUCTURE CHANGES OF SYNAPSES IN THE HIPPOCAMPUS. 2019 8 2834 42 FOLIC ACID MODULATES MATRIX METALLOPROTEINASE-2 EXPRESSION, ALLEVIATES NEUROPATHIC PAIN, AND IMPROVES FUNCTIONAL RECOVERY IN SPINAL CORD-INJURED RATS. BACKGROUND: THE MOLECULAR UNDERPINNINGS OF SPINAL CORD INJURY (SCI) ASSOCIATED WITH NEUROPATHIC PAIN (NP) ARE UNKNOWN. RECENT STUDIES HAVE DEMONSTRATED THAT MATRIX METALLOPROTEINASES (MMPS) SUCH AS MMP2 PLAY A CRITICAL ROLE IN INDUCING NP FOLLOWING SCI. PROMOTER METHYLATION OF MMPS IS KNOWN TO SUPPRESS THEIR TRANSCRIPTION AND REDUCE NP. IN THIS CONTEXT, IT HAS BEEN SHOWN IN RODENTS THAT FOLIC ACID (FA), AN FDA APPROVED DIETARY SUPPLEMENT AND KEY METHYL DONOR IN THE CENTRAL NERVOUS SYSTEM (CNS), INCREASES AXONAL REGENERATION AND REPAIR OF INJURED CNS IN PART VIA METHYLATION. PURPOSE: BASED ON ABOVE OBSERVATIONS, IN THIS STUDY, WE TEST WHETHER FA COULD DECREASE MMP2 EXPRESSION AND THEREBY DECREASE SCI-INDUCED NP. METHODS: SPRAGUE-DAWLEY MALE RATS WEIGHING 250-270 G RECEIVED CONTUSION SPINAL CORD INJURIES (CSCIS) WITH A CUSTOM SPINAL CORD IMPACTOR DEVICE THAT DROPS A 10 G WEIGHT FROM A HEIGHT OF 12.5 MM. THE INJURED RATS RECEIVED EITHER I.P. INJECTIONS OF FA (80 MICROG/KG) OR WATER (CONTROL) 3 DAYS PRIOR AND 17 DAYS POST-CSCI (MID PHASE) OR FOR 3 DAYS PRE-CSCI AND 14 DAYS POST-CSCI ENDING ON THE 42ND DAY OF CSCI (LATE PHASE). THE FUNCTIONAL NEUROLOGICAL DEFICITS DUE TO CSCI WERE THEN ASSESSED BY BASSO, BEATTIE, AND BRESNAHAN (BBB) SCORES EITHER ON POST-IMPACTION DAYS 0 THROUGH 18 POST-CSCI (MID PHASE) OR ON DAYS 0, 2, 7, 14, 21, 28, 35, AND 42 (LATE PHASE). BASELINE MEASUREMENTS WERE TAKEN THE DAY BEFORE STARTING TREATMENTS. THERMAL HYPERALGESIA (TH) TESTING FOR PAIN WAS PERFORMED ON 4 DAYS PRE-CSCI (BASELINE DATA) AND ON DAYS 18, 21, 28, 35, AND 42 POST-CSCI. FOLLOWING TH TESTING, ANIMALS WERE EUTHANIZED AND SPINAL CORDS HARVESTED FOR MMP-2 EXPRESSION ANALYSIS. RESULT: THE FA-TREATED GROUPS SHOWED HIGHER BBB SCORES DURING MID PHASE (DAY 18) AND IN LATE PHASE (DAY 42) OF INJURY COMPARED TO CONTROLS, SUGGESTING ENHANCED FUNCTIONAL RECOVERY. THERE IS A TRANSIENT DECLINE IN TH IN ANIMALS FROM THE FA-TREATED GROUP COMPARED TO CONTROLS WHEN TESTED ON DAYS 18, 21, 28, AND 35, INDICATIVE OF A DECREASE IN NP. HOWEVER, WHEN TESTED 25 DAYS AFTER STOPPING FA ADMINISTRATION ON DAY 42 OF CSCI, NO SIGNIFICANT DIFFERENCE IN TH WAS OBSERVED BETWEEN FA-TREATED AND CONTROL ANIMALS. WESTERN BLOT ANALYSIS OF THE INJURED SPINAL CORD FROM FA-TREATED ANIMALS SHOWED SIGNIFICANT DECLINE IN MMP2 EXPRESSION COMPARED TO SPINAL CORD SAMPLES FROM WATER-TREATED CONTROLS. CONCLUSION: TOGETHER, THESE DATA SUGGEST THAT FA COULD ALLEVIATE NP AND IMPROVE FUNCTIONAL RECOVERY POST-SCI, POSSIBLY BY REDUCING THE EXPRESSION OF MMP2. FURTHER STUDIES WILL OPEN UP A NOVEL AND EASY NATURAL THERAPY, IDEAL FOR CLINICAL TRANSLATION WITH MINIMAL SIDE EFFECTS, FOR MANAGING SCI-INDUCED NP. SUCH STUDIES MIGHT ALSO THROW LIGHT ON A POSSIBLE EPIGENETIC MECHANISM IN FA-INDUCED RECOVERY AFTER SCI. 2017 9 593 35 BET PROTEIN INHIBITION REGULATES CYTOKINE PRODUCTION AND PROMOTES NEUROPROTECTION AFTER SPINAL CORD INJURY. BACKGROUND: SPINAL CORD INJURY (SCI) USUALLY CAUSES A DEVASTATING LIFELONG DISABILITY FOR PATIENTS. AFTER A TRAUMATIC LESION, DISRUPTION OF THE BLOOD-SPINAL CORD BARRIER INDUCES THE INFILTRATION OF MACROPHAGES INTO THE LESION SITE AND THE ACTIVATION OF RESIDENT GLIAL CELLS, WHICH RELEASE CYTOKINES AND CHEMOKINES. THESE EVENTS RESULT IN A PERSISTENT INFLAMMATION, WHICH HAS BOTH DETRIMENTAL AND BENEFICIAL EFFECTS, BUT EVENTUALLY LIMITS FUNCTIONAL RECOVERY AND CONTRIBUTES TO THE APPEARANCE OF NEUROPATHIC PAIN. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC READERS THAT REGULATE THE EXPRESSION OF INFLAMMATORY GENES BY INTERACTING WITH ACETYLATED LYSINE RESIDUES. WHILE BET INHIBITORS ARE A PROMISING THERAPEUTIC STRATEGY FOR CANCER, LITTLE IS KNOWN ABOUT THEIR IMPLICATION AFTER SCI. THUS, THE CURRENT STUDY WAS AIMED TO INVESTIGATE THE ANTI-INFLAMMATORY ROLE OF BET INHIBITORS IN THIS PATHOLOGIC CONDITION. METHODS: WE EVALUATED THE EFFECTIVENESS OF THE BET INHIBITOR JQ1 TO MODIFY MACROPHAGE REACTIVITY IN VITRO AND TO MODULATE INFLAMMATION IN A SCI MICE MODEL. WE ANALYZED THE EFFECTS OF BET INHIBITION IN PRO-INFLAMMATORY AND ANTI-INFLAMMATORY CYTOKINE PRODUCTION IN VITRO AND IN VIVO. WE DETERMINED THE EFFECTIVENESS OF BET INHIBITION IN TISSUE SPARING, INFLAMMATION, NEURONAL PROTECTION, AND BEHAVIORAL OUTCOME AFTER SCI. RESULTS: WE HAVE FOUND THAT THE BET INHIBITOR JQ1 REDUCED THE LEVELS OF PRO-INFLAMMATORY MEDIATORS AND INCREASED THE EXPRESSION OF ANTI-INFLAMMATORY CYTOKINES. A PROLONGED TREATMENT WITH JQ1 ALSO DECREASED REACTIVITY OF MICROGLIA/MACROPHAGES, ENHANCED NEUROPROTECTION AND FUNCTIONAL RECOVERY, AND ACUTELY REDUCED NEUROPATHIC PAIN AFTER SCI. CONCLUSIONS: BET PROTEIN INHIBITION IS AN EFFECTIVE TREATMENT TO REGULATE CYTOKINE PRODUCTION AND PROMOTE NEUROPROTECTION AFTER SCI. THESE NOVEL RESULTS DEMONSTRATE FOR THE FIRST TIME THAT TARGETING BET PROTEINS IS AN ENCOURAGING APPROACH FOR SCI REPAIR AND A POTENTIAL STRATEGY TO TREAT OTHER INFLAMMATORY PATHOLOGIES. 2019 10 4405 30 MOLECULAR ADAPTATIONS OF THE BLOOD-BRAIN BARRIER PROMOTE STRESS RESILIENCE VS. DEPRESSION. PRECLINICAL AND CLINICAL STUDIES SUGGEST THAT INFLAMMATION AND VASCULAR DYSFUNCTION CONTRIBUTE TO THE PATHOGENESIS OF MAJOR DEPRESSIVE DISORDER (MDD). CHRONIC SOCIAL STRESS ALTERS BLOOD-BRAIN BARRIER (BBB) INTEGRITY THROUGH LOSS OF TIGHT JUNCTION PROTEIN CLAUDIN-5 (CLDN5) IN MALE MICE, PROMOTING PASSAGE OF CIRCULATING PROINFLAMMATORY CYTOKINES AND DEPRESSION-LIKE BEHAVIORS. THIS EFFECT IS PROMINENT WITHIN THE NUCLEUS ACCUMBENS, A BRAIN REGION ASSOCIATED WITH MOOD REGULATION; HOWEVER, THE MECHANISMS INVOLVED ARE UNCLEAR. MOREOVER, COMPENSATORY RESPONSES LEADING TO PROPER BEHAVIORAL STRATEGIES AND ACTIVE RESILIENCE ARE UNKNOWN. HERE WE IDENTIFY ACTIVE MOLECULAR CHANGES WITHIN THE BBB ASSOCIATED WITH STRESS RESILIENCE THAT MIGHT SERVE A PROTECTIVE ROLE FOR THE NEUROVASCULATURE. WE ALSO CONFIRM THE RELEVANCE OF SUCH CHANGES TO HUMAN DEPRESSION AND ANTIDEPRESSANT TREATMENT. WE SHOW THAT PERMISSIVE EPIGENETIC REGULATION OF CLDN5 EXPRESSION AND LOW ENDOTHELIUM EXPRESSION OF REPRESSIVE CLDN5-RELATED TRANSCRIPTION FACTOR FOXO1 ARE ASSOCIATED WITH STRESS RESILIENCE. REGION- AND ENDOTHELIAL CELL-SPECIFIC WHOLE TRANSCRIPTOMIC ANALYSES REVEALED MOLECULAR SIGNATURES ASSOCIATED WITH STRESS VULNERABILITY VS. RESILIENCE. WE IDENTIFIED PROINFLAMMATORY TNFALPHA/NFKAPPAB SIGNALING AND HDAC1 AS MEDIATORS OF STRESS SUSCEPTIBILITY. PHARMACOLOGICAL INHIBITION OF STRESS-INDUCED INCREASE IN HDAC1 ACTIVITY RESCUED CLDN5 EXPRESSION IN THE NAC AND PROMOTED RESILIENCE. IMPORTANTLY, WE CONFIRMED CHANGES IN HDAC1 EXPRESSION IN THE NAC OF DEPRESSED PATIENTS WITHOUT ANTIDEPRESSANT TREATMENT IN LINE WITH CLDN5 LOSS. CONVERSELY, MANY OF THESE DELETERIOUS CLDN5-RELATED MOLECULAR CHANGES WERE REDUCED IN POSTMORTEM NAC FROM ANTIDEPRESSANT-TREATED SUBJECTS. THESE FINDINGS REINFORCE THE IMPORTANCE OF CONSIDERING STRESS-INDUCED NEUROVASCULAR PATHOLOGY IN DEPRESSION AND PROVIDE THERAPEUTIC TARGETS TO TREAT THIS MOOD DISORDER AND PROMOTE RESILIENCE. 2020 11 3977 25 LONG-TERM EFFECT OF POST-TRAUMATIC STRESS IN ADOLESCENCE ON DENDRITE DEVELOPMENT AND H3K9ME2/BDNF EXPRESSION IN MALE RAT HIPPOCAMPUS AND PREFRONTAL CORTEX. EXPOSURE TO A HARSH ENVIRONMENT IN EARLY LIFE INCREASES IN THE RISK OF POST-TRAUMATIC STRESS DISORDER (PTSD) OF AN INDIVIDUAL. BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) PLAYS AN IMPORTANT ROLE IN NEURODEVELOPMENT IN DEVELOPMENTAL STAGES. BOTH CHRONIC AND TRAUMATIC STRESSES INDUCE A DECREASE IN THE LEVEL OF BDNF AND REDUCE NEURAL PLASTICITY, WHICH IS LINKED TO THE PATHOGENESIS OF PTSD. ALSO, STUDIES HAVE SHOWN THAT STRESS ALTERS THE EPIGENETIC MARKER H3K9ME2, WHICH CAN BIND TO THE PROMOTER REGION OF THE BDNF GENE AND REDUCE BDNF PROTEIN LEVEL. HOWEVER, THE LONG-TERM EFFECTS OF TRAUMATIC STRESS DURING ADOLESCENCE ON H3K9ME2, BDNF EXPRESSION AND DENDRITE DEVELOPMENT ARE NOT WELL-KNOWN. THE PRESENT STUDY ESTABLISHED A MODEL OF PTSD IN ADOLESCENT RATS USING AN INESCAPABLE FOOT SHOCK (IFS) PROCEDURE. ANXIETY-LIKE BEHAVIORS, SOCIAL INTERACTION BEHAVIOR AND MEMORY FUNCTION WERE ASSESSED BY THE OPEN FIELD TEST, ELEVATED PLUS MAZE TEST, THREE-CHAMBER SOCIABILITY TEST AND MORRIS WATER MAZE TEST. IN ADDITION, NEURONAL DEVELOPMENT AND H3K9ME2/BDNF EXPRESSION IN HIPPOCAMPUS (HIP) AND PREFRONTAL CORTEX (PFC) WERE EVALUATED BY GOLGI STAINING, WESTERN BLOTTING, QRT-PCR ANALYSIS AND CHIP-QPCR ANALYSIS. ADDITIONALLY, THE UNC0642, A SMALL MOLECULE INHIBITOR OF HISTONE METHYLTRANSFERASE (EHMT2) WAS USED FOR INTERVENTION. THE RESULTS SHOWED THAT THE IFS PROCEDURE INDUCED THE PTSD-LIKE BEHAVIORS IN RATS, RESULTED IN FEWER DENDRITE BRANCHES AND SHORTER DENDRITE LENGTH IN CA1 OF HIP AND PFC, INCREASED H3K9ME2 LEVEL AND DECREASED BDNF EXPRESSION IN HIP AND PFC. ALSO, ALTHOUGH ALL THE CHANGES CAN PERSIST TO ADULTHOOD, UNC0642 ADMINISTRATION RELIEVED MOST OF ALTERATIONS. OUR STUDY SUGGESTS THAT TRAUMATIC STRESS IN ADOLESCENCE LEADS TO IMMEDIATE AND LONG-TERM MENTAL DISORDERS, NEURONAL MORPHOLOGICAL CHANGES, LOWER BDNF LEVEL AND INCREASED H3K9ME2 LEVEL IN THE HIP AND PFC, INDICATING THAT H3K9ME2/BDNF DYSFUNCTION PLAYS A KEY ROLE IN PATHOGENESIS OF PTSD. 2020 12 2448 23 EPIGENETIC SUPPRESSION OF GAD65 EXPRESSION MEDIATES PERSISTENT PAIN. CHRONIC PAIN IS A COMMON NEUROLOGICAL DISEASE INVOLVING LASTING, MULTIFACETED MALADAPTATIONS RANGING FROM GENE MODULATION TO SYNAPTIC DYSFUNCTION AND EMOTIONAL DISORDERS. SUSTAINED PATHOLOGICAL STIMULI IN MANY DISEASES ALTER THE OUTPUT ACTIVITIES OF CERTAIN GENES THROUGH EPIGENETIC MODIFICATIONS, BUT IT IS UNCLEAR HOW EPIGENETIC MECHANISMS OPERATE IN THE DEVELOPMENT OF CHRONIC PAIN. WE SHOW HERE THAT IN THE RAT BRAINSTEM NUCLEUS RAPHE MAGNUS, WHICH IS IMPORTANT FOR CENTRAL MECHANISMS OF CHRONIC PAIN, PERSISTENT INFLAMMATORY AND NEUROPATHIC PAIN EPIGENETICALLY SUPPRESSES GAD2 (ENCODING GLUTAMIC ACID DECARBOXYLASE 65 (GAD65)) TRANSCRIPTION THROUGH HISTONE DEACETYLASE (HDAC)-MEDIATED HISTONE HYPOACETYLATION, RESULTING IN IMPAIRED GAMMA-AMINOBUTYRIC ACID (GABA) SYNAPTIC INHIBITION. GAD2 KNOCKOUT MICE SHOWED SENSITIZED PAIN BEHAVIOR AND IMPAIRED GABA SYNAPTIC FUNCTION IN THEIR BRAINSTEM NEURONS. IN WILD-TYPE BUT NOT GAD2 KNOCKOUT MICE, HDAC INHIBITORS STRONGLY INCREASED GAD65 ACTIVITY, RESTORED GABA SYNAPTIC FUNCTION AND RELIEVED SENSITIZED PAIN BEHAVIOR. THESE FINDINGS SUGGEST GAD65 AND HDACS AS POTENTIAL THERAPEUTIC TARGETS IN AN EPIGENETIC APPROACH TO THE TREATMENT OF CHRONIC PAIN. 2011 13 1803 13 EFFECT OF PROLONGED EMOTIONAL AND PAIN STRESS ON THE CONTENT OF METHYLCYTOSINE-BINDING PROTEIN MECP2 IN NUCLEI OF HIPPOCAMPAL NEURONS IN RATS WITH DIFFERENT EXCITABILITY OF THE NERVOUS SYSTEM. IN RATS WITH LOW EXCITABILITY THRESHOLD OF THE NERVOUS SYSTEM DEMONSTRATING SIGNIFICANT AND PERSISTENT BEHAVIORAL DISORDERS UNDER STRESS CONDITIONS, THE CONTENT OF METHYLCYTOSINE-BINDING PROTEIN MECP2 IN NEURONAL NUCLEI OF HIPPOCAMPAL FIELD CA3 DECREASED OVER 2 WEEKS AFTER LONG-TERM EMOTIONAL AND PAIN STRESS. IT WAS HYPOTHESIZED THAT PROTEIN MECP2 TRIGGERS EPIGENETIC CHANGES IN DNA THAT UNDERLIE "STRESS MEMORY". 2006 14 2827 24 FLUOXETINE INCREASES HIPPOCAMPAL NEUROGENESIS AND INDUCES EPIGENETIC FACTORS BUT DOES NOT IMPROVE FUNCTIONAL RECOVERY AFTER TRAUMATIC BRAIN INJURY. THE SELECTIVE SEROTONIN REUPTAKE INHIBITOR FLUOXETINE INDUCES HIPPOCAMPAL NEUROGENESIS, STIMULATES MATURATION AND SYNAPTIC PLASTICITY OF ADULT HIPPOCAMPAL NEURONS, AND REDUCES MOTOR/SENSORY AND MEMORY IMPAIRMENTS IN SEVERAL CNS DISORDERS. IN THE SETTING OF TRAUMATIC BRAIN INJURY (TBI), ITS EFFECTS ON NEUROPLASTICITY AND FUNCTION HAVE YET TO BE THOROUGHLY INVESTIGATED. HERE WE EXAMINED THE EFFICACY OF FLUOXETINE AFTER A MODERATE TO SEVERE TBI, PRODUCED BY A CONTROLLED CORTICAL IMPACT. THREE DAYS AFTER TBI OR SHAM SURGERY, MICE WERE TREATED WITH FLUOXETINE (10 MG/KG/D) OR VEHICLE FOR 4 WEEKS. TO EVALUATE THE EFFECTS OF FLUOXETINE ON NEUROPLASTICITY, HIPPOCAMPAL NEUROGENESIS AND EPIGENETIC MODIFICATION WERE STUDIED. STEREOLOGIC ANALYSIS OF THE DENTATE GYRUS REVEALED A SIGNIFICANT INCREASE IN DOUBLECORTIN-POSITIVE CELLS IN BRAIN-INJURED ANIMALS TREATED WITH FLUOXETINE RELATIVE TO CONTROLS, A FINDING CONSISTENT WITH ENHANCED HIPPOCAMPAL NEUROGENESIS. EPIGENETIC MODIFICATIONS, INCLUDING AN INCREASE IN HISTONE 3 ACETYLATION AND INDUCTION OF METHYL-CPG-BINDING PROTEIN, A TRANSCRIPTION FACTOR INVOLVED IN DNA METHYLATION, WERE LIKEWISE SEEN BY IMMUNOHISTOCHEMISTRY AND QUANTITATIVE WESTERN IMMUNOBLOTS, RESPECTIVELY, IN BRAIN-INJURED ANIMALS TREATED WITH FLUOXETINE. TO DETERMINE IF FLUOXETINE IMPROVES NEUROLOGICAL OUTCOMES AFTER TBI, GAIT FUNCTION AND SPATIAL LEARNING AND MEMORY WERE ASSESSED BY THE CATWALK-ASSISTED GAIT TEST AND BARNES MAZE TEST, RESPECTIVELY. NO DIFFERENCES IN THESE PARAMETERS WERE SEEN BETWEEN FLUOXETINE- AND VEHICLE-TREATED ANIMALS. THUS WHILE FLUOXETINE ENHANCED NEUROPLASTICITY IN THE HIPPOCAMPUS AFTER TBI, ITS CHRONIC ADMINISTRATION DID NOT RESTORE LOCOMOTOR FUNCTION OR AMELIORATE MEMORY DEFICITS. 2011 15 2826 25 FLUOXETINE EPIGENETICALLY ALTERS THE CAMKIIALPHA PROMOTER IN NUCLEUS ACCUMBENS TO REGULATE DELTAFOSB BINDING AND ANTIDEPRESSANT EFFECTS. CHRONIC SOCIAL DEFEAT STRESS IN MICE PRODUCES A SUSCEPTIBLE PHENOTYPE CHARACTERIZED BY SEVERAL BEHAVIORAL ABNORMALITIES CONSISTENT WITH HUMAN DEPRESSION THAT ARE REVERSED BY CHRONIC BUT NOT ACUTE EXPOSURE TO ANTIDEPRESSANT MEDICATIONS. RECENT WORK IN ADDICTION MODELS DEMONSTRATES THAT THE TRANSCRIPTION FACTOR DELTAFOSB AND PROTEIN KINASE CALMODULIN-DEPENDENT PROTEIN KINASE II (CAMKII) ARE CO-REGULATED IN NUCLEUS ACCUMBENS (NAC), A BRAIN REWARD REGION IMPLICATED IN BOTH ADDICTION AND DEPRESSION MODELS INCLUDING SOCIAL DEFEAT. PREVIOUS WORK HAS ALSO DEMONSTRATED THAT DELTAFOSB IS INDUCED IN NAC AFTER CHRONIC SOCIAL DEFEAT STRESS OR AFTER CHRONIC ANTIDEPRESSANT TREATMENT, WHEREIN IT MEDIATES A PRO-RESILIENCE OR ANTIDEPRESSANT-LIKE PHENOTYPE. HERE, USING CHROMATIN IMMUNOPRECIPITATION ASSAYS, WE FOUND THAT DELTAFOSB BINDS THE CAMKIIALPHA GENE PROMOTER IN NAC AND THAT THIS BINDING INCREASES AFTER MICE ARE EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS. PARADOXICALLY, CHRONIC EXPOSURE TO THE ANTIDEPRESSANT FLUOXETINE REDUCES BINDING OF DELTAFOSB TO THE CAMKIIALPHA PROMOTER AND REDUCES CAMKII EXPRESSION IN NAC, DESPITE THE FACT THAT DELTAFOSB IS INDUCED UNDER THESE CONDITIONS. THESE DATA SUGGEST A NOVEL EPIGENETIC MECHANISM OF ANTIDEPRESSANT ACTION, WHEREBY FLUOXETINE INDUCES SOME CHROMATIN CHANGE AT THE CAMKIIALPHA PROMOTER, WHICH BLOCKS THE DELTAFOSB BINDING. INDEED, CHRONIC FLUOXETINE REDUCES ACETYLATION AND INCREASES LYSINE-9 DIMETHYLATION OF HISTONE H3 AT THE CAMKIIALPHA PROMOTER IN NAC, EFFECTS ALSO SEEN IN DEPRESSED HUMANS EXPOSED TO ANTIDEPRESSANTS. OVEREXPRESSION OF CAMKII IN NAC BLOCKS FLUOXETINE'S ANTIDEPRESSANT EFFECTS IN THE CHRONIC SOCIAL DEFEAT PARADIGM, WHEREAS INHIBITION OF CAMKII ACTIVITY IN NAC MIMICS FLUOXETINE EXPOSURE. THESE FINDINGS SUGGEST THAT EPIGENETIC SUPPRESSION OF CAMKIIALPHA EXPRESSION IN NAC IS BEHAVIORALLY RELEVANT AND OFFER A NOVEL PATHWAY FOR POSSIBLE THERAPEUTIC INTERVENTION IN DEPRESSION AND RELATED SYNDROMES. 2014 16 4304 32 MICRORNA-223 PROTECTS NEURONS FROM DEGENERATION IN EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS. MULTIPLE SCLEROSIS IS A CHRONIC INFLAMMATORY, DEMYELINATING, AND NEURODEGENERATIVE DISEASE AFFECTING THE BRAIN, SPINAL CORD AND OPTIC NERVES. NEURONAL DAMAGE IS TRIGGERED BY VARIOUS HARMFUL FACTORS THAT ENGAGE DIVERSE SIGNALLING CASCADES IN NEURONS; THUS, THERAPEUTIC APPROACHES TO PROTECT NEURONS WILL NEED TO FOCUS ON AGENTS THAT CAN TARGET MULTIPLE BIOLOGICAL PROCESSES. WE HAVE THEREFORE FOCUSED OUR ATTENTION ON MICRORNAS: SMALL NON-CODING RNAS THAT PRIMARILY FUNCTION AS POST-TRANSCRIPTIONAL REGULATORS THAT TARGET MESSENGER RNAS AND REPRESS THEIR TRANSLATION INTO PROTEINS. A SINGLE MICRORNA CAN TARGET MANY FUNCTIONALLY RELATED MESSENGER RNAS MAKING MICRORNAS POWERFUL EPIGENETIC REGULATORS. DYSREGULATION OF MICRORNAS HAS BEEN DESCRIBED IN MANY NEURODEGENERATIVE DISEASES INCLUDING MULTIPLE SCLEROSIS. HERE, WE REPORT THAT TWO MICRORNAS, MIR-223-3P AND MIR-27A-3P, ARE UPREGULATED IN NEURONS IN THE EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS MOUSE MODEL OF CNS INFLAMMATION AND IN GREY MATTER-CONTAINING MULTIPLE SCLEROSIS LESIONS. PRIOR WORK HAS SHOWN PERIPHERAL BLOOD MONONUCLEAR CELL CONDITIONED MEDIA CAUSES SUBLETHAL DEGENERATION OF NEURONS IN CULTURE. WE FIND OVEREXPRESSION OF MIR-27A-3P OR MIR-223-3P PROTECTS DISSOCIATED CORTICAL NEURONS FROM CONDITION MEDIA MEDIATED DEGENERATION. INTRODUCTION OF MIR-223-3P IN VIVO IN MOUSE RETINAL GANGLION CELLS PROTECTS THEIR AXONS FROM DEGENERATION IN EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS. IN SILICO ANALYSIS REVEALED THAT MESSENGER RNAS INVOLVED IN GLUTAMATE RECEPTOR SIGNALLING ARE ENRICHED AS MIR-27A-3P AND MIR-223-3P TARGETS. WE OBSERVE THAT ANTAGONISM OF NMDA AND AMPA TYPE GLUTAMATE RECEPTORS PROTECTS NEURONS FROM CONDITION MEDIA DEPENDENT DEGENERATION. OUR RESULTS SUGGEST THAT MIR-223-3P AND MIR-27A-3P ARE UPREGULATED IN RESPONSE TO INFLAMMATION TO MEDIATE A COMPENSATORY NEUROPROTECTIVE GENE EXPRESSION PROGRAM THAT DESENSITIZES NEURONS TO GLUTAMATE BY TARGETING MESSENGER RNAS INVOLVED IN GLUTAMATE RECEPTOR SIGNALLING. 2019 17 6388 31 THE ROLE OF SIRT1 IN THE BASOLATERAL AMYGDALA IN DEPRESSION-LIKE BEHAVIORS IN MICE. PREVIOUS INVESTIGATIONS HAVE IMPLICATED THE BASOLATERAL AMYGDALA (BLA) EPIGENETIC MECHANISMS IN THE PATHOPHYSIOLOGY OF DEPRESSION. SIRT1 IS A NAD+-DEPENDENT CLASS III HISTONE DEACETYLASE, WIDELY EXPRESSES IN BLA. HOWEVER, EPIGENETIC MECHANISMS IN THE BLA UNDER THE REGULATION OF SIRT1 IN THE DEPRESSION ARE LARGELY UNCHARACTERIZED. UNDER THE CHRONIC UNPREDICTABLE CHRONIC MILD STRESS (CUMS) MOUSE MODEL, WE USED ADENO-ASSOCIATED VIRAL VECTORS (AAV) THAT ENCODED SIRT1-SHRNA OR SIRT1 TO SPECIFICALLY KNOCKDOWN OR OVEREXPRESS SIRT1 IN BLA NEURONS, RESPECTIVELY. CUMS PROCEDURE INDUCED SIGNIFICANT DEPRESSION SYMPTOMS INCLUDING THE DECREASED SUCROSE PREFERENCE, THE LESS BODYWEIGHT GAINED, THE DECREASED IMMOBILE LATENCY AND THE INCREASED IMMOBILE TIME BOTH IN FORCED SWIM TEST (FST) AND TAIL SUSPENSION TEST (TST). KNOCKDOWN OF SIRT1 IN BLA GLUTAMATERGIC NEURONS REVERSED THESE DEPRESSION-LIKE BEHAVIORS AND RESTORED THE SYNAPTIC ABNORMALITIES. OVEREXPRESSION OF SIRT1 IN BLA GLUTAMATERGIC NEURONS INDUCED DEPRESSION-LIKE BEHAVIORS IN NON-STRESSED CONTROL MICE. THE RESULT OF PROTEIN EXPRESSIONS AND ULTRASTRUCTURAL CHANGES WERE CONSISTENT WITH THE BEHAVIORAL RESULTS. OUR STUDY SUGGESTED THAT DOWNREGULATION OF SIRT1 IN BLA HAS CERTAIN BENEFICIAL EFFECT ON CUMS-INDUCED DEPRESSION-LIKE BEHAVIORS SUCH AS ANOREXIA, ANHEDONIA, HOPELESSNESS AND DESPAIR. IN ADDITION, THE INCREASED EXPRESSION OF SIRT1 MAY BE THE IMMEDIATE CAUSE OF DEPRESSIVE-LIKE SYMPTOMS. THE ABNORMAL EXPRESSION OF SIRT1 MAY AFFECT THE TRANSCRIPTIONAL REGULATION MECHANISM AND SIGNALING PROTEIN ACETYLATION, AFFECTING NEUROPLASTICITY AND ULTIMATELY CONTRIBUTE TO MDD. IN THE STRESS-SUSCEPTIBLE MICE, THESE TWO MECHANISMS MAY CO-EXIST, BUT THE SPECIFIC MECHANISM NEEDS FURTHER RESEARCH. 2021 18 2353 20 EPIGENETIC REGULATION OF OPIOID-INDUCED HYPERALGESIA, DEPENDENCE, AND TOLERANCE IN MICE. REPEATED ADMINISTRATION OF OPIOIDS SUCH AS MORPHINE INDUCES PERSISTENT BEHAVIORAL CHANGES INCLUDING OPIOID-INDUCED HYPERALGESIA (OIH), TOLERANCE, AND PHYSICAL DEPENDENCE. IN THE CURRENT WORK WE EXPLORED HOW THE BALANCE OF HISTONE ACETYLTRANSFERASE (HAT) VERSUS HISTONE DEACETYLASE (HDAC) MIGHT REGULATE THESE MORPHINE-INDUCED CHANGES. NOCICEPTIVE THRESHOLDS, ANALGESIA, AND PHYSICAL DEPENDENCE WERE ASSESSED DURING AND FOR A PERIOD OF SEVERAL WEEKS AFTER MORPHINE EXPOSURE. TO PROBE THE ROLES OF HISTONE ACETYLATION, THE HAT INHIBITOR CURCUMIN OR A SELECTIVE HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) WAS ADMINISTERED DAILY TO GROUPS OF ANIMALS. HISTONE ACETYLATION IN SPINAL CORD WAS ASSESSED BY WESTERN BLOT AND IMMUNOHISTOCHEMISTRY. CONCURRENT ADMINISTRATION OF CURCUMIN WITH MORPHINE FOR 4 DAYS SIGNIFICANTLY REDUCED DEVELOPMENT OF OPIOID-INDUCED MECHANICAL ALLODYNIA, THERMAL HYPERALGESIA, TOLERANCE, AND PHYSICAL DEPENDENCE. CONVERSELY, THE HDAC INHIBITOR SAHA ENHANCED THESE RESPONSES. INTERESTINGLY, SAHA TREATMENT AFTER THE TERMINATION OF OPIOID ADMINISTRATION SUSTAINED THESE BEHAVIORAL CHANGES FOR AT LEAST 4 WEEKS. HISTONE H3 ACETYLATION IN THE DORSAL HORN OF THE SPINAL CORD WAS INCREASED AFTER CHRONIC MORPHINE TREATMENT, BUT H4 ACETYLATION WAS UNCHANGED. MOREOVER, WE OBSERVED A DECREASE IN HDAC ACTIVITY IN THE SPINAL CORDS OF MORPHINE-TREATED MICE WHILE OVERALL HAT ACTIVITY WAS UNCHANGED, SUGGESTING A SHIFT TOWARD A STATE OF ENHANCED HISTONE ACETYLATION. PERSPECTIVE: THE CURRENT STUDY INDICATES THAT EPIGENETIC MECHANISMS PLAY A CRUCIAL ROLE IN OPIOID-INDUCED LONG-LASTING NEUROPLASTICITY. THESE RESULTS PROVIDE NEW SIGHT INTO UNDERSTANDING THE MECHANISMS OF OPIOID-INDUCED NEUROPLASTICITY AND SUGGEST NEW STRATEGIES TO LIMIT OPIOID ABUSE POTENTIAL AND INCREASE THE VALUE OF THESE DRUGS AS ANALGESICS. 2013 19 2300 21 EPIGENETIC REGULATION OF BDNF EXPRESSION IN THE PRIMARY SENSORY NEURONS AFTER PERIPHERAL NERVE INJURY: IMPLICATIONS IN THE DEVELOPMENT OF NEUROPATHIC PAIN. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS KNOWN TO BE UP-REGULATED IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, AND TO CONTRIBUTE TO NEUROPATHIC PAIN. HERE, WE FOUND THAT THERMAL HYPERALGESIA AND MECHANICAL ALLODYNIA AT DAY 7 POST-INJURY WERE INHIBITED ONLY WHEN ANTI-BDNF ANTIBODY WAS INTRATHECALLY ADMINISTRATED AT DAY 2 POST-INJURY. CONSISTENT WITH BEHAVIORAL RESULTS, WESTERN BLOT ANALYSIS SHOWED THAT THE EXPRESSION LEVELS OF BDNF PROTEIN IN THE SPINAL DORSAL HORN WERE MARKEDLY INDUCED DURING EARLY STAGE POST-INJURY. MOREOVER, THE MAXIMAL INCREASE IN BDNF MRNA EXPRESSION IN THE DRG WAS OBSERVED AT DAY 1 POST-INJURY, AND SIGNIFICANTLY ELEVATED LEVELS WERE SUSTAINED FOR AT LEAST 14 DAYS. FOUR OF FIVE BDNF MRNA TRANSCRIPTS WERE UP-REGULATED AFTER NERVE INJURY, AND THE MOST INDUCIBLE TRANSCRIPT WAS EXON I. USING A CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, WE FOUND THAT NERVE INJURY PROMOTES HISTONE H3 AND H4 ACETYLATION, TRANSCRIPTIONALLY ACTIVE MODIFICATIONS, AT BDNF PROMOTER I AT DAY 1 POST-INJURY, AND THE LEVELS OF HISTONE ACETYLATION REMAIN ELEVATED FOR AT LEAST 7 DAYS. TAKEN TOGETHER, OUR FINDINGS SUGGEST THAT AN INITIAL INCREASE IN BDNF EXON I EXPRESSION CONTROLLED BY EPIGENETIC MECHANISMS MIGHT HAVE A CRUCIAL ROLE IN THE DEVELOPMENT OF NEUROPATHIC PAIN. 2013 20 5051 30 PHARMACOLOGICAL RESCUE OF NOCICEPTIVE HYPERSENSITIVITY AND OXYTOCIN ANALGESIA IMPAIRMENT IN A RAT MODEL OF NEONATAL MATERNAL SEPARATION. OXYTOCIN (OT), KNOWN FOR ITS NEUROHORMONAL EFFECTS AROUND BIRTH, HAS RECENTLY BEEN SUGGESTED FOR BEING A CRITICAL DETERMINANT IN NEURODEVELOPMENTAL DISORDERS. THIS HYPOTHALAMIC NEUROPEPTIDE EXERTS A POTENT ANALGESIC EFFECT THROUGH AN ACTION ON THE NOCICEPTIVE SYSTEM. THIS ENDOGENOUS CONTROL OF PAIN HAS AN IMPORTANT ADAPTIVE VALUE BUT MIGHT BE ALTERED BY EARLY LIFE STRESS, POSSIBLY CONTRIBUTING TO ITS LONG-TERM CONSEQUENCES ON PAIN RESPONSES AND ASSOCIATED COMORBIDITIES. WE TESTED THIS HYPOTHESIS USING A RAT MODEL OF NEONATAL MATERNAL SEPARATION (NMS) KNOWN TO INDUCE LONG-TERM CONSEQUENCES ON SEVERAL BRAIN FUNCTIONS INCLUDING CHRONIC STRESS, ANXIETY, ALTERED SOCIAL BEHAVIOR, AND VISCERAL HYPERSENSITIVITY. WE FOUND THAT ADULT RATS WITH A HISTORY OF NMS WERE HYPERSENSITIVE TO NOXIOUS MECHANICAL/THERMAL HOT STIMULI AND TO INFLAMMATORY PAIN. WE FAILED TO OBSERVE OT RECEPTOR-MEDIATED STRESS-INDUCED ANALGESIA AND OT ANTIHYPERALGESIA AFTER CARRAGEENAN INFLAMMATION. THESE ALTERATIONS WERE PARTIALLY RESCUED IF NMS PUPS WERE TREATED BY INTRAPERITONEAL DAILY INJECTION DURING NMS WITH OT OR ITS DOWNSTREAM SECOND MESSENGER ALLOPREGNANOLONE. THE INVOLVEMENT OF EPIGENETIC CHANGES IN THESE ALTERATIONS WAS CONFIRMED SINCE NEONATAL TREATMENT WITH THE HISTONE DEACETYLASE INHIBITOR SAHA, NOT ONLY NORMALIZED NOCICEPTIVE SENSITIVITIES BUT ALSO RESTORED OT RECEPTOR-MEDIATED STRESS-INDUCED ANALGESIA AND THE ENDOGENOUS ANTIHYPERALGESIA IN INFLAMED NMS RATS. THERE IS GROWING EVIDENCE IN THE LITERATURE THAT EARLY LIFE STRESS MIGHT IMPAIR THE NOCICEPTIVE SYSTEM ONTOGENY AND FUNCTION. THIS STUDY SUGGESTS THAT THESE ALTERATIONS MIGHT BE RESTORED WHILE STIMULATING OT RECEPTOR SIGNALING OR HISTONE DEACETYLASE INHIBITORS, USING MOLECULES THAT ARE CURRENTLY AVAILABLE OR PART OF CLINICAL TRIALS FOR OTHER PATHOLOGIES. 2018