1 6654 131 UPDATE ON PSEUDOEXFOLIATION SYNDROME PATHOGENESIS AND ASSOCIATIONS WITH INTRAOCULAR PRESSURE, GLAUCOMA AND SYSTEMIC DISEASES. PURPOSE OF REVIEW: PSEUDOEXFOLIATION (PEX) SYNDROME IS A COMMON AGE-RELATED DISORDER AFFECTING INTRAOCULAR AND EXTRAOCULAR TISSUES. THIS REVIEW FOCUSES ON RECENT PUBLICATIONS RELATED WITH THE PATHOGENESIS AND ASSOCIATIONS OF PEX SYNDROME WITH INTRAOCULAR PRESSURE (IOP), GLAUCOMA AND SYSTEMIC DISEASES. RECENT FINDINGS: IN PEX TISSUES, EXPRESSION OF LYSYL OXIDASE-LIKE 1 (LOXL1) WAS FOUND TO BE MARKEDLY DYSREGULATED. THIS MAY ADVERSELY AFFECT ELASTIN METABOLISM AND LEAD TO ELASTOTIC ALTERATION IN TISSUES SUCH AS LAMINA CRIBROSA. THERE IS INCREASING EVIDENCE THAT CELLULAR STRESS CONDITIONS AND LOW-GRADE CHRONIC INFLAMMATORY PROCESSES ARE INVOLVED IN THE PATHOGENESIS OF PEX. ALTHOUGH THERE IS AN INCREASED RISK FOR GLAUCOMA DEVELOPMENT IN PATIENTS WITH PEX AND OCULAR HYPERTENSION AS COMPARED WITH NON-PEX PATIENTS WITH OCULAR HYPERTENSION, LOXL1 SINGLE NUCLEOTIDE POLYMORPHISMS WERE NOT ASSOCIATED WITH INTRAOCULAR PRESSURE (IOP) DIFFERENCES. LACK OF ASSOCIATION OF PEX WITH ALL-CAUSE MORTALITY OR DEMENTIA HAS BEEN REPORTED RECENTLY. THE ASSOCIATION WITH VASCULAR DISEASES IS NOT CONSISTENT AMONG DIFFERENT STUDIES. SUMMARY: DESPITE THE HIGH PREVALENCE OF THE LOXL1 VARIANTS IN THE GENERAL POPULATION, A MUCH LOWER PROPORTION OF THE POPULATION DEVELOPS PEX, SUGGESTING THAT IN ADDITION TO LOXL1, OTHER GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS MAY CONTRIBUTE TO THE DEVELOPMENT OF PEX. ALSO, LOXL1 CANNOT HELP TO IDENTIFY THOSE WITH PEX AT INCREASED RISK FOR GLAUCOMA DEVELOPMENT. INCREASED RISK FOR GLAUCOMA DEVELOPMENT IN PEX PATIENTS WHO PRESENT WITH INCREASED IOP MAY BE RELATED TO OTHER FACTORS BEYOND IOP, CONTRIBUTING TO INCREASED VULNERABILITY OF THE OPTIC NERVE TO GLAUCOMA DEVELOPMENT IN THE PRESENCE OF PEX. 2015 2 1904 33 ENHANCED RETINAL GANGLION CELL SURVIVAL IN GLAUCOMA BY HYPOXIC POSTCONDITIONING AFTER DISEASE ONSET. THE NEUROPROTECTIVE EFFICACY OF ADAPTIVE EPIGENETICS, WHEREIN BENEFICIAL GENE EXPRESSION CHANGES ARE INDUCED BY NONHARMFUL "CONDITIONING" STIMULI, IS NOW WELL ESTABLISHED IN SEVERAL ACUTE, PRECLINICAL CENTRAL NERVOUS SYSTEM INJURY MODELS. RECENTLY, IN A MOUSE MODEL OF GLAUCOMA, WE DEMONSTRATED RETINAL GANGLION CELL (RGC) PROTECTION BY REPETITIVELY "PRECONDITIONING" WITH HYPOXIA PRIOR TO DISEASE ONSET, INDICATING AN EPIGENETIC APPROACH MAY ALSO YIELD BENEFITS IN CHRONIC NEURODEGENERATIVE DISEASE. HEREIN, WE DETERMINED WHETHER PRESENTING THE REPETITIVE HYPOXIC STIMULUS AFTER DISEASE INITIATION [REPETITIVE HYPOXIC "POSTCONDITIONING" (RH-POST)] COULD AFFORD SIMILAR FUNCTIONAL AND MORPHOLOGIC PROTECTION AGAINST GLAUCOMATOUS RGC INJURY. CHRONIC ELEVATIONS IN INTRAOCULAR PRESSURE (IOP) WERE INDUCED UNILATERALLY IN ADULT MALE C57BL/6 MICE BY EPISCLERAL VEIN LIGATION. MICE WERE RANDOMIZED TO AN RH-POST [1 H OF SYSTEMIC HYPOXIA (11% OXYGEN) EVERY OTHER DAY, STARTING 4 DAYS AFTER IOP ELEVATION] OR AN UNTREATED CONTROL GROUP. AFTER 3 WEEKS OF EXPERIMENTAL GLAUCOMA, THE 21-27% REDUCTION AND 5-25% PROLONGATION IN FLASH VISUAL-EVOKED POTENTIAL AMPLITUDES AND LATENCIES, RESPECTIVELY, AND THE 30% IMPAIRMENT IN VISUAL ACUITY WERE ROBUSTLY IMPROVED IN RH-POST-TREATED MICE, AS WAS THE 17% LOSS IN RGC SOMA NUMBER AND 20% REDUCTION IN AXON INTEGRITY. THESE PROTECTIVE EFFECTS WERE OBSERVED WITHOUT RH-POST AFFECTING IOP. THE PRESENT FINDINGS DEMONSTRATE THAT FUNCTIONAL AND MORPHOLOGIC PROTECTION OF RGCS CAN BE REALIZED BY STIMULATING EPIGENETIC RESPONSES DURING THE EARLY STAGES OF DISEASE, AND THUS CONSTITUTE A NEW CONCEPTUAL APPROACH TO GLAUCOMA THERAPEUTICS. 2015 3 809 27 CHANGES IN CLASS I AND IIB HDACS BY DELTA-OPIOID IN CHRONIC RAT GLAUCOMA MODEL. PURPOSE: THIS STUDY DETERMINES IF DELTA-OPIOID RECEPTOR AGONIST (I.E. SNC-121)-INDUCED EPIGENETIC CHANGES VIA REGULATION OF HISTONE DEACETYLASES (HDACS) FOR RETINAL GANGLION CELL (RGC) NEUROPROTECTION IN GLAUCOMA MODEL. METHODS: INTRAOCULAR PRESSURE WAS RAISED IN RAT EYES BY INJECTING 2M HYPERTONIC SALINE INTO THE LIMBAL VEINS. SNC-121 (1 MG/KG; I.P.) WAS ADMINISTERED TO THE ANIMALS FOR 7 DAYS. RETINAS WERE COLLECTED AT DAYS 7 AND 42, POST-INJURY FOLLOWED BY MEASUREMENT OF HDAC ACTIVITIES, MRNA, AND PROTEIN EXPRESSION BY ENZYME ASSAY, QUANTITATIVE REAL-TIME PCR (QRT-PCR), WESTERN BLOTTING, AND IMMUNOHISTOCHEMISTRY. RESULTS: THE VISUAL ACUITY, CONTRAST SENSITIVITY, AND PATTERN ELECTRORETINOGRAMS (ERGS) WERE DECLINED IN OCULAR HYPERTENSIVE ANIMALS, WHICH WERE SIGNIFICANTLY IMPROVED BY SNC-121 TREATMENT. CLASS I AND IIB HDACS ACTIVITIES WERE SIGNIFICANTLY INCREASED AT DAYS 7 AND 42 IN OCULAR HYPERTENSIVE ANIMALS. THE MRNA AND PROTEIN EXPRESSION OF HDAC 1 WAS INCREASED BY 1.33 +/- 0.07-FOLD AND 20.2 +/- 2.7%, HDAC 2 BY 1.4 +/- 0.05-FOLD AND 17.0 +/- 2.4%, HDAC 3 BY 1.4 +/- 0.06-FOLD AND 17.4 +/- 3.4%, AND HDAC 6 BY 1.5 +/- 0.09-FOLD AND 15.1 +/- 3.3% AT DAY 7, POST-INJURY. BOTH THE MRNA AND PROTEIN EXPRESSION OF HDACS WERE POTENTIATED FURTHER AT DAY 42 IN OCULAR HYPERTENSIVE ANIMALS. HDAC ACTIVITIES, MRNA, AND PROTEIN EXPRESSION WERE BLOCKED BY SNC-121 TREATMENT AT DAYS 7 AND 42 IN OCULAR HYPERTENSIVE ANIMALS. CONCLUSIONS: DATA SUGGESTS THAT CLASS I AND IIB HDACS ARE ACTIVATED AND UPREGULATED DURING EARLY STAGES OF GLAUCOMA. EARLY INTERVENTION WITH DELTA-OPIOID RECEPTOR ACTIVATION RESULTED IN THE PROLONGED SUPPRESSION OF CLASS I AND IIB HDACS ACTIVITIES AND EXPRESSION, WHICH MAY, IN PART, PLAY A CRUCIAL ROLE IN RGC NEUROPROTECTION. 2020 4 123 33 A SYSTEMATIC REVIEW, META-ANALYSIS, AND NETWORK ANALYSIS OF DIAGNOSTIC MICRORNAS IN GLAUCOMA. GLAUCOMA IS A CHRONIC NEURODEGENERATIVE PROCESS OF THE OPTIC NERVE THAT IS THE LEADING CAUSE OF BLINDNESS WORLDWIDE, AND EARLY DIAGNOSIS OF THE DISEASE COULD GREATLY AFFECT PATIENTS' PROGNOSES. THE PATHOPHYSIOLOGY OF GLAUCOMA IS COMPLICATED BY A COMBINATION OF GENETIC AND EPIGENETIC FACTORS. DECIPHERING THE EARLY DIAGNOSTIC BIOMARKERS IN GLAUCOMA COULD ATTENUATE THE DISEASE'S GLOBAL BURDEN AND HELP US UNDERSTAND THE EXACT MECHANISMS INVOLVED IN GLAUCOMA. THE MICRORNAS ARE MEMBERS OF A LARGER FAMILY OF NON-CODING RNAS THAT PLAY AN ESSENTIAL ROLE IN THE EPIGENETIC BASIS OF GLAUCOMA. A SYSTEMATIC STUDY AND META-ANALYSIS OF DIAGNOSTIC MICRORNAS IN GLAUCOMA, JOINTLY WITH NETWORK ANALYSIS OF TARGET GENES, WERE CARRIED OUT ON PUBLISHED PAPERS ASSESSING DIFFERENTIALLY EXPRESSED MICRORNAS IN HUMAN SUBJECTS. IN TOTAL, 321 ARTICLES WERE FOUND, AND, AFTER SCREENING, SIX STUDIES WERE ELIGIBLE FOR FURTHER ANALYSIS. 52 DIFFERENTIALLY EXPRESSED MICRORNAS WERE FOUND, OF WHICH 28 AND 24 WERE UP-REGULATED AND DOWN-REGULATED, RESPECTIVELY. ONLY 12 MICRORNAS WERE QUALIFIED FOR META-ANALYSIS, WITH OVERALL SENSITIVITY AND SPECIFICITY OF 80% AND 74%, RESPECTIVELY. THEN, USING NETWORK ANALYSIS, IT BECAME APPARENT THAT THE VEGF-A, AKT1, CXCL12, AND HRAS GENES WERE THE MOST IMPORTANT TARGETS FOR THE MICRORNAS. PERTURBATIONS IN WNT SIGNALING, PROTEIN TRANSPORT, AND EXTRACELLULAR MATRIX ORGANIZATION PATHWAYS WERE DISCOVERED TO BE IMPORTANT IN THE ETIOLOGY OF GLAUCOMA USING THE COMMUNITY DETECTION APPROACH. THIS STUDY TRIES TO UNCOVER THE PROMISING MICRORNAS AND THEIR TARGET GENES THAT GOVERN THE EPIGENETICS OF GLAUCOMA. 2023 5 2473 26 EPIGENETIC TREATMENTS OF ADULT RATS PROMOTE RECOVERY FROM VISUAL ACUITY DEFICITS INDUCED BY LONG-TERM MONOCULAR DEPRIVATION. IN MAMMALS THE DEVELOPMENT OF THE VISUAL SYSTEM MAY BE ALTERED DURING A SENSITIVE PERIOD BY MODIFYING THE VISUAL INPUT TO ONE OR BOTH EYES. THESE PLASTIC PROCESSES ARE REDUCED AFTER THE END OF THE SENSITIVE PERIOD. IT HAS BEEN PROPOSED THAT REDUCED LEVELS OF PLASTICITY ARE AT THE BASIS OF THE LACK OF RECOVERY FROM EARLY VISUAL DEPRIVATION OBSERVED IN ADULT ANIMALS. A DEVELOPMENTAL DOWNREGULATION OF EXPERIENCE-DEPENDENT REGULATION OF HISTONE ACETYLATION HAS RECENTLY BEEN FOUND TO BE INVOLVED IN CLOSING THE SENSITIVE PERIOD. THEREFORE, WE TESTED WHETHER PHARMACOLOGICAL EPIGENETIC TREATMENTS INCREASING HISTONE ACETYLATION COULD BE USED TO REVERSE VISUAL ACUITY DEFICITS INDUCED BY LONG-TERM MONOCULAR DEPRIVATION INITIATED DURING THE SENSITIVE PERIOD. WE FOUND THAT CHRONIC INTRAPERITONEAL ADMINISTRATION OF VALPROIC ACID OR SODIUM BUTYRATE (TWO DIFFERENT HISTONE DEACETYLASES INHIBITORS) TO LONG-TERM MONOCULARLY DEPRIVED ADULT RATS COUPLED WITH REVERSE LID-SUTURING CAUSED A COMPLETE RECOVERY OF VISUAL ACUITY, TESTED ELECTROPHYSIOLOGICALLY AND BEHAVIORALLY. THUS, MANIPULATIONS OF THE EPIGENETIC MACHINERY CAN BE USED TO PROMOTE FUNCTIONAL RECOVERY FROM EARLY ALTERATIONS OF SENSORY INPUT IN THE ADULT CORTEX. 2010 6 6023 28 THE BET PROTAC INHIBITOR DBET6 PROTECTS AGAINST RETINAL DEGENERATION AND INHIBITS THE CGAS-STING IN RESPONSE TO LIGHT DAMAGE. BACKGROUND: CHRONIC INFLAMMATION SIGNIFICANTLY CONTRIBUTES TO PHOTORECEPTOR DEATH IN BLINDING RETINAL DISEASES SUCH AS AGE-RELATED MACULAR DEGENERATION (AMD) AND RETINITIS PIGMENTOSA (RP). BROMODOMAIN AND EXTRATERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC READERS THAT ACT AS KEY PROINFLAMMATORY FACTORS. WE RECENTLY FOUND THE FIRST-GENERATION BET INHIBITOR JQ1 ALLEVIATED SODIUM IODATE-INDUCED RETINAL DEGENERATION BY SUPPRESSING CGAS-STING INNATE IMMUNITY. HERE, WE INVESTIGATED THE EFFECTS AND MECHANISM OF DBET6, A PROTEOLYSIS?TARGETING CHIMERA (PROTAC) SMALL MOLECULE THAT SELECTIVELY DEGRADES BET BY THE UBIQUITIN?PROTEASOME SYSTEM, IN LIGHT-INDUCED RETINAL DEGENERATION. METHODS: MICE WERE EXPOSED TO BRIGHT LIGHT TO INDUCE RETINAL DEGENERATION, AND THE ACTIVATION OF CGAS-STING WAS DETERMINED BY RNA-SEQUENCING AND MOLECULAR BIOLOGY. RETINAL FUNCTION, MORPHOLOGY, PHOTORECEPTOR VIABILITY AND RETINAL INFLAMMATION WERE EXAMINED IN THE PRESENCE AND ABSENCE OF DBET6 TREATMENT. RESULTS: INTRAPERITONEAL INJECTION OF DBET6 LED TO THE RAPID DEGRADATION OF BET PROTEIN IN THE RETINA WITHOUT DETECTABLE TOXICITY. DBET6 IMPROVED RETINAL RESPONSIVENESS AND VISUAL ACUITY AFTER LIGHT DAMAGE (LD). DBET6 ALSO REPRESSED LD-INDUCED RETINAL MACROPHAGES/MICROGLIA ACTIVATION, MULLER CELL GLIOSIS, PHOTORECEPTOR DEATH AND RETINAL DEGENERATION. ANALYSIS OF SINGLE-CELL RNA-SEQUENCING RESULTS REVEALED CGAS-STING COMPONENTS WERE EXPRESSED IN RETINAL MICROGLIA. LD LED TO DRAMATIC ACTIVATION OF THE CGAS-STING PATHWAY, WHEREAS DBET6 SUPPRESSED LD-INDUCED STING EXPRESSION IN REACTIVE MACROPHAGES/MICROGLIA AND THE RELATED INFLAMMATORY RESPONSE. CONCLUSIONS: THIS STUDY INDICATES TARGETED DEGRADATION OF BET BY DBET6 EXERTS NEUROPROTECTIVE EFFECTS BY INHIBITING CGAS-STING IN REACTIVE RETINAL MACROPHAGES/MICROGLIA, AND IS EXPECTED TO BECOME A NEW STRATEGY FOR TREATMENT OF RETINAL DEGENERATION. 2023 7 5690 32 SILENCING OF FEM1CR3 GENE EXPRESSION IN THE DBA/2J MOUSE PRECEDES RETINAL GANGLION CELL DEATH AND IS ASSOCIATED WITH HISTONE DEACETYLASE ACTIVITY. PURPOSE: DOWNREGULATION OF NORMAL GENE EXPRESSION IN DYING RETINAL GANGLION CELLS HAS BEEN DOCUMENTED IN BOTH ACUTE AND CHRONIC MODELS OF OPTIC NERVE DISEASE. THE AUTHORS EXAMINED THE MECHANISM AND TIMING OF THIS PHENOMENON IN DBA/2J MICE, USING GENETICALLY MODIFIED SUBSTRAINS OF THIS INBRED LINE. METHODS: DBA/2J MICE, DOUBLY CONGENIC FOR THE BAX MUTANT ALLELE AND THE GANGLION CELL REPORTER GENE FEM1C(ROSA3) (R3), WERE EVALUATED TO ELUCIDATE THE TIMING OF LOSS OF NORMAL GENE EXPRESSION DURING THE APOPTOTIC PROCESS. THE LOCALIZATION OF HISTONE DEACETYLASE 3 (HDAC3) AND NUCLEAR HISTONE H4 ACETYLATION WERE EXAMINED BY IMMUNOFLUORESCENCE IN DYING CELLS. THE ROLE OF HDACS IN GENE SILENCING DURING GLAUCOMA WAS INTERROGATED USING THE GLOBAL HDAC INHIBITOR TRICHOSTATIN A (TSA). RESULTS: SILENCING OF THE R3 ALLELE OCCURRED IN BAX(-/-) GANGLION CELLS, INDICATING THAT THIS PROCESS PRECEDED THE COMMITTED STEP OF THE INTRINSIC APOPTOTIC PATHWAY. WEEKLY TSA TREATMENT, BETWEEN THE AGES OF 6 AND 10 MONTHS, WAS ABLE TO ATTENUATE THE LOSS OF R3 EXPRESSION IN THE RETINA, BUT HAD NO EFFECT ON OPTIC NERVE DEGENERATION. DYING CELLS IN AGING DBA/2J MICE EXHIBITED NUCLEAR LOCALIZATION OF HDAC3 AND A DECREASE IN THE LEVEL OF H4 ACETYLATION. CONCLUSIONS: RETINAL GANGLION CELLS EXHIBIT A LOSS OF NORMAL GENE EXPRESSION AS AN EARLY (PRE-BAX INVOLVEMENT) PART OF THEIR APOPTOTIC PROGRAM DURING GLAUCOMATOUS DEGENERATION. THIS PROCESS CAN BE AMELIORATED, BUT NOT COMPLETELY BLOCKED, USING HDAC INHIBITORS. EPIGENETIC CHANGES TO ACTIVE CHROMATIN, SUCH AS DEACETYLATION, MAY BE MEDIATED BY HDAC3 IN DYING NEURONS. 2012 8 3332 27 HISTONE DEACETYLASE INHIBITOR-INDUCED EMERGENCE OF SYNAPTIC DELTA-OPIOID RECEPTORS AND BEHAVIORAL ANTINOCICEPTION IN PERSISTENT NEUROPATHIC PAIN. THE EFFICACY OF OPIOIDS IN PATIENTS WITH CHRONIC NEUROPATHIC PAIN REMAINS CONTROVERSIAL. ALTHOUGH ACTIVATION OF DELTA-OPIOID RECEPTORS (DORS) IN THE BRAINSTEM REDUCES INFLAMMATION-INDUCED PERSISTENT HYPERALGESIA, IT IS NOT EFFECTIVE UNDER PERSISTENT NEUROPATHIC PAIN CONDITIONS AND THESE CLINICAL PROBLEMS REMAIN LARGELY UNKNOWN. IN THIS STUDY, BY USING A CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE IN RATS, WE FOUND THAT IN THE BRAINSTEM NUCLEUS RAPHE MAGNUS (NRM), DORS EMERGED ON THE SURFACE MEMBRANE OF CENTRAL SYNAPTIC TERMINALS ON DAY 3 AFTER CCI SURGERY AND DISAPPEARED ON DAY 14. HISTONE DEACETYLASE (HDAC) INHIBITORS MICROINJECTED INTO THE NRM IN VIVO INCREASED THE LEVEL OF SYNAPTOSOMAL DOR PROTEIN AND NRM INFUSION OF DOR AGONISTS PRODUCING AN ANTINOCICEPTIVE EFFECT IN A NERVE GROWTH FACTOR (NGF) SIGNALING-DEPENDENT MANNER. IN VITRO, IN CCI RAT SLICES INCUBATED WITH HDAC INHIBITORS, DOR AGONISTS SIGNIFICANTLY INHIBITED EPSCS. THIS EFFECT WAS BLOCKED BY TYROSINE RECEPTOR KINASE A ANTAGONISTS. CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT NRM INFUSION OF HDAC INHIBITORS IN CCI RATS INCREASED THE LEVEL OF HISTONE H4 ACETYLATION AT NGF GENE PROMOTER REGIONS. NGF WAS INFUSED INTO THE NRM OR INCUBATED CCI RAT SLICES DROVE DORS TO THE SURFACE MEMBRANE OF SYNAPTIC TERMINALS. TAKEN TOGETHER, EPIGENETIC UPREGULATION OF NGF ACTIVITY BY HDAC INHIBITORS IN THE NRM PROMOTES THE TRAFFICKING OF DORS TO PAIN-MODULATING NEURONAL SYNAPSES UNDER NEUROPATHIC PAIN CONDITIONS, LEADING TO DELTA-OPIOID ANALGESIA. THESE FINDINGS INDICATE THAT THERAPEUTIC USE OF DOR AGONISTS COMBINED WITH HDAC INHIBITORS MIGHT BE EFFECTIVE IN CHRONIC NEUROPATHIC PAIN MANAGEMENTS. 2016 9 1430 22 DIFFERENTIAL EXPRESSION OF SOX11 AND BDNF MRNA ISOFORMS IN THE INJURED AND REGENERATING NERVOUS SYSTEMS. IN BOTH THE CENTRAL NERVOUS SYSTEM (CNS) AND THE PERIPHERAL NERVOUS SYSTEM (PNS), AXONAL INJURY INDUCES CHANGES IN NEURONAL GENE EXPRESSION. IN THE PNS, A RELATIVELY WELL-CHARACTERIZED ALTERATION IN TRANSCRIPTIONAL ACTIVATION IS KNOWN TO PROMOTE AXONAL REGENERATION. THIS TRANSCRIPTIONAL CASCADE INCLUDES THE NEUROTROPHIN BDNF AND THE TRANSCRIPTION FACTOR SOX11. ALTHOUGH BOTH MOLECULES ACT TO FACILITATE SUCCESSFUL AXON REGENERATION IN THE PNS, THIS PROCESS DOES NOT OCCUR IN THE CNS. THE PRESENT STUDY EXAMINES THE DIFFERENTIAL EXPRESSION OF SOX11 AND BDNF MRNA ISOFORMS IN THE PNS AND CNS USING THREE EXPERIMENTAL PARADIGMS AT DIFFERENT TIME POINTS: (I) THE ACUTELY INJURED CNS (RETINA AFTER OPTIC NERVE CRUSH) AND PNS (DORSAL ROOT GANGLION AFTER SCIATIC NERVE CRUSH), (II) A CNS REGENERATION MODEL (RETINA AFTER OPTIC NERVE CRUSH AND INDUCED REGENERATION); AND (III) THE RETINA DURING A CHRONIC FORM OF CENTRAL NEURODEGENERATION (THE DBA/2J GLAUCOMA MODEL). WE FIND AN INITIAL INCREASE OF SOX11 IN BOTH PNS AND CNS AFTER INJURY; HOWEVER, THE EXPRESSION OF BDNF ISOFORMS IS HIGHER IN THE PNS RELATIVE TO THE CNS. SUSTAINED UPREGULATION OF SOX11 IS SEEN IN THE INJURED RETINA FOLLOWING REGENERATION TREATMENT, WHILE THE EXPRESSION OF TWO BDNF MRNA ISOFORMS IS SUPPRESSED. FURTHERMORE, TWO ISOFORMS OF SOX11 WITH DIFFERENT 3'UTR LENGTHS ARE PRESENT IN THE RETINA, AND THE LONG ISOFORM IS SPECIFICALLY UPREGULATED IN LATER STAGES OF GLAUCOMA. THESE RESULTS PROVIDE INSIGHT INTO THE MOLECULAR CASCADES ACTIVE DURING AXONAL INJURY AND REGENERATION IN MAMMALIAN NEURONS. 2017 10 6039 31 THE CHEMOKINE RECEPTOR CXCR2 SUPPORTS NOCICEPTIVE SENSITIZATION AFTER TRAUMATIC BRAIN INJURY. CHRONIC PAIN AFTER TRAUMATIC BRAIN INJURY (TBI) IS VERY COMMON, BUT THE MECHANISMS LINKING TBI TO PAIN AND THE PAIN-RELATED INTERACTIONS OF TBI WITH PERIPHERAL INJURIES ARE POORLY UNDERSTOOD. CHEMOKINE RECEPTORS PLAY AN IMPORTANT ROLE IN BOTH PAIN AND BRAIN INJURY. IN THE CURRENT WORK, WE PURSUED THE HYPOTHESIS THAT THE EPIGENETICALLY REGULATED CXC CHEMOKINE RECEPTOR 2 (CXCR2) IS A CRUCIAL MODULATOR OF NOCICEPTIVE SENSITIZATION INDUCED BY TBI. FOR THESE STUDIES, WE USED THE RAT LATERAL FLUID PERCUSSION MODEL OF TBI. HISTONE ACTYLTRANSFERASE ACTIVITY WAS BLOCKED USING ANACARDIC ACID BEGINNING IMMEDIATELY FOLLOWING INJURY, OR DELAYED FOR SEVEN DAYS PRIOR TO ADMINISTRATION. THE SELECTIVE CXCR2 ANTAGONIST SCH527123 ADMINISTERED SYSTEMICALLY OR INTRATHECALLY WAS USED TO PROBE THE ROLE OF CHEMOKINE SIGNALING ON MECHANICAL HINDPAW SENSITIZATION AFTER TBI. THE EXPRESSION OF THE CXCR2 RECEPTOR WAS ACCOMPLISHED USING REAL-TIME PCR, IMMUNOHISTOCHEMISTRY, AND WESTERN BLOTTING, WHILE EPIGENETIC REGULATION WAS ASSESSED USING CHROMATIN IMMUNOPRECIPITATION ASSAY. THE SPINAL LEVELS OF SEVERAL PAIN-RELATED MEDIATORS INCLUDING CXCL1, AN ENDOGENOUS LIGAND FOR CXCR2, AS WELL AS BRAIN-DERIVED NEUROTROPHIC FACTOR AND PRODYNORPHIN WERE MEASURED BY ENZYME-LINKED IMMUNOSORBENT ASSAY. WE OBSERVED THAT ANACARDIC ACID POTENTLY BLOCKED AND REVERSED MECHANICAL HINDPAW SENSITIZATION AFTER TBI. THE SAME DRUG WAS ABLE TO PREVENT THE UPREGULATION OF CXCR2 AFTER TBI, BUT DID NOT AFFECT THE SPINAL EXPRESSION OF OTHER PAIN MEDIATORS. ON THE OTHER HAND, BOTH SYSTEMICALLY AND INTRATHECALLY ADMINISTERED SCH527123 REVERSED HINDPAW ALLODYNIA AFTER TBI. MOST OF THE SPINAL CXCR2 APPEARED TO BE EXPRESSED BY SPINAL CORD NEURONS. CHROMATIN IMMUNOPRECIPITATION EXPERIMENTS DEMONSTRATED TBI-ENHANCED ASSOCIATION OF THE CXCR2 PROMOTER WITH ACETYLATED-H3K9 HISTONE PROTEIN THAT WAS ALSO REVERSIBLE USING ANACARDIC ACID. TAKEN TOGETHER, OUR FINDINGS SUGGESTED THAT TBI CAUSES THE UPREGULATION OF SPINAL CXCR2 THROUGH AN EPIGENETIC MECHANISM ULTIMATELY SUPPORTING NOCICEPTIVE SENSITIZATION. THE USE OF CXCR2 ANTAGONISTS MAY, THEREFORE, BE USEFUL IN PAIN RESULTING FROM TBI. 2017 11 2300 25 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 12 3832 22 INVOLVEMENT OF SPINAL SIRT1 IN DEVELOPMENT OF CHRONIC CONSTRICTION INJURY INDUCED NEUROPATHIC PAIN IN RATS. IT IS KNOWN THAT THE EPIGENETIC PROCESS OF HISTONE ACETYLATION IS INVOLVED IN THE NEUROPATHIC PAIN. THE AIM OF THIS STUDY WAS TO DETERMINE WHETHER SIRTUIN TYPE 1 (SIRT1), AN NAD(+) DEPENDENT DEACETYLASE, AFFECTED ALLODYNIA AND HYPERALGESIA IN NEUROPATHIC PAIN. THE NEUROPATHIC PAIN MODEL WAS ESTABLISHED BY LIGATURE OF THE RIGHT SCIATIC NERVE TO INDUCE CHRONIC CONSTRICTION INJURY (CCI) IN RATS. HISTONE ACETYLTRANSFERASE (HAT) ACTIVITY WAS INCREASED AND, AND HISTONE DEACETYLASE (HDAC) ACTIVITY WAS DECLINED IN TISSUE OF THE SPINAL DORSA HORN IN CCI RATES BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA). THE PERSISTENT HYPERALGESIA AND ALLODYNIA CAUSED BY CCI WERE ASSOCIATED WITH DOWNREGULATION OF SIRT1 AND UPREGULATION OF ACETYLATED-H3 (AC-H3) IN TISSUE OF THE SPINAL CORD BY WESTERN BLOT ASSAY, WHICH WAS REVERSED AFTER INTRATHECAL INJECTION OF SIRT1 AGONIST SRT1720. SRT1720 TREATMENT ACHIEVED ANALGESIC THROUGH INHIBITING THE ACETYLATION OF NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND BLOCKING THE RELEASES OF THE INFLAMMATORY FACTORS INCLUDING TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) AND INTERLEUKIN (IL)-6 BY MEANS OF WESTERN BLOT AND REAL-TIME QUANTITATIVE PCR (RT-PCR), RESPECTIVELY. TAKEN TOGETHER, THESE DATA SUGGEST THAT SIRT1 IN THE SPINAL CORD PLAYS AN IMPORTANT ROLE IN THE NEUROPATHIC PAIN IN THE RAT MODEL. 2018 13 2365 23 EPIGENETIC REGULATION OF SPINAL CXCR2 SIGNALING IN INCISIONAL HYPERSENSITIVITY IN MICE. BACKGROUND: THE REGULATION OF GENE EXPRESSION IN NOCICEPTIVE PATHWAYS CONTRIBUTES TO THE INDUCTION AND MAINTENANCE OF PAIN SENSITIZATION. HISTONE ACETYLATION IS A KEY EPIGENETIC MECHANISM CONTROLLING CHROMATIN STRUCTURE AND GENE EXPRESSION. CHEMOKINE CC MOTIF RECEPTOR 2 (CXCR2) IS A PROINFLAMMATORY RECEPTOR IMPLICATED IN NEUROPATHIC AND INFLAMMATORY PAIN AND IS KNOWN TO BE REGULATED BY HISTONE ACETYLATION IN SOME SETTINGS. THE AUTHORS SOUGHT TO INVESTIGATE THE ROLE OF HISTONE ACETYLATION ON SPINAL CXCR2 SIGNALING AFTER INCISION. METHODS: GROUPS OF 5-8 MICE UNDERWENT HIND PAW INCISION. SUBEROYLANILIDE HYDROXAMIC ACID AND ANACARDIC ACID WERE USED TO INHIBIT HISTONE DEACETYLASE AND HISTONE ACETYLTRANSFERASE, RESPECTIVELY. BEHAVIORAL MEASURES OF THERMAL AND MECHANICAL SENSITIZATION AS WELL AS HYPERALGESIC PRIMING WERE USED. BOTH MESSAGE RNA QUANTIFICATION AND CHROMATIN IMMUNOPRECIPITATION ANALYSIS WERE USED TO STUDY THE REGULATION OF CXCR2 AND LIGAND EXPRESSION. FINALLY, THE SELECTIVE CXCR2 ANTAGONIST SB225002 WAS ADMINISTERED INTRATHECALLY TO REVEAL THE FUNCTION OF SPINAL CXCR2 RECEPTORS AFTER HIND PAW INCISION. RESULTS: SUBEROYLANILIDE HYDROXAMIC ACID SIGNIFICANTLY EXACERBATED MECHANICAL SENSITIZATION AFTER INCISION. CONVERSELY, ANACARDIC ACID REDUCED INCISIONAL SENSITIZATION AND ALSO ATTENUATED INCISION-INDUCED HYPERALGESIC PRIMING. OVERALL, ACETYLATED HISTONE H3 AT LYSINE 9 WAS INCREASED IN SPINAL CORD TISSUES AFTER INCISION, AND ENHANCED ASSOCIATION OF ACETYLATED HISTONE H3 AT LYSINE 9 WITH THE PROMOTER REGIONS OF CXCR2 AND KERATINOCYTE-DERIVED CHEMOKINE (CXCL1) WAS OBSERVED AS WELL. BLOCKING CXCR2 REVERSED MECHANICAL HYPERSENSITIVITY AFTER HIND PAW INCISION. CONCLUSIONS: HISTONE MODIFICATION IS AN IMPORTANT EPIGENETIC MECHANISM REGULATING INCISION-INDUCED NOCICEPTIVE SENSITIZATION. THE SPINAL CXCR2 SIGNALING PATHWAY IS ONE EPIGENETICALLY REGULATED PATHWAY CONTROLLING EARLY AND LATENT SENSITIZATION AFTER INCISION. 2013 14 5402 30 REDUCTION OF SIRT1-MEDIATED EPIGENETIC UPREGULATION OF NAV1.7 CONTRIBUTES TO OXALIPLATIN-INDUCED NEUROPATHIC PAIN. BACKGROUND: CLINICALLY, NEUROPATHIC PAIN IS A SEVERE SIDE EFFECT OF OXALIPLATIN CHEMOTHERAPY, WHICH USUALLY LEADS TO DOSE REDUCTION OR CESSATION OF TREATMENT. DUE TO THE UNAWARENESS OF DETAILED MECHANISMS OF OXALIPLATIN-INDUCED NEUROPATHIC PAIN, IT IS DIFFICULT TO DEVELOP AN EFFECTIVE THERAPY AND LIMITS ITS CLINICAL USE. OBJECTIVES: THE AIM OF THE PRESENT STUDY WAS TO IDENTIFY THE ROLE OF SIRTUIN 1 (SIRT1) REDUCTION IN EPIGENETIC REGULATION OF THE EXPRESSION OF VOLTAGE-GATED SODIUM CHANNELS 1.7 (NAV1.7) IN THE DORSAL ROOT GANGLION (DRG) DURING OXALIPLATIN-INDUCED NEUROPATHIC PAIN. STUDY DESIGN: CONTROLLED ANIMAL STUDY. SETTING: UNIVERSITY LABORATORY. METHODS: THE VON FREY TEST WAS PERFORMED TO EVALUATE PAIN BEHAVIOR IN RATS. REAL-TIME QUANTITATIVE POLYMERASE CHAIN REACTION, WESTERN BLOTTING, ELECTROPHYSIOLOGICAL RECORDING, CHROMATIN IMMUNOPRECIPITATION, AND SMALL INTERFERING RNA (SIRNA) WERE USED TO ILLUSTRATE THE MECHANISMS. RESULTS: IN THE PRESENT STUDY, WE FOUND THAT BOTH THE ACTIVITY AND EXPRESSION OF SIRT1 WERE SIGNIFICANTLY DECREASED IN RAT DRG FOLLOWING OXALIPLATIN TREATMENT. THE ACTIVATOR OF SIRT1, RESVERATROL, NOT ONLY INCREASED THE ACTIVITY AND EXPRESSION OF SIRT1, BUT ALSO ATTENUATED THE MECHANICAL ALLODYNIA FOLLOWING OXALIPLATIN TREATMENT. IN ADDITION, LOCAL KNOCKDOWN OF SIRT1 BY INTRATHECAL INJECTION OF SIRT1 SIRNA CAUSED MECHANICAL ALLODYNIA IN NAIVE RATS. BESIDES, OXALIPLATIN TREATMENT ENHANCED THE ACTION POTENTIAL FIRING FREQUENCY OF DRG NEURONS AND THE EXPRESSION OF NAV1.7 IN DRG AND ACTIVATION OF SIRT1 BY RESVERATROL REVERSED THIS EFFECT. FURTHERMORE, BLOCKING NAV1.7 BY PROTX II (A SELECTIVE NAV1.7 CHANNEL BLOCKER) REVERSED OXALIPLATIN-INDUCED MECHANICAL ALLODYNIA. IN ADDITION, HISTONE H3 HYPERACETYLATION AT THE NAV1.7 PROMOTER IN DRG OF RATS FOLLOWING OXALIPLATIN TREATMENT WAS SIGNIFICANTLY SUPPRESSED BY ACTIVATION OF SIRT1 WITH RESVERATROL. MOREOVER, BOTH THE EXPRESSION OF NAV1.7 AND HISTONE H3 ACETYLATION AT THE NAV1.7 PROMOTER WERE UPREGULATED IN THE DRG BY LOCAL KNOCKDOWN OF SIRT1 WITH SIRT1 SIRNA IN NAIVE RATS. LIMITATIONS: MORE UNDERLYING MECHANISM(S) OF SIRT1 REDUCTION AFTER OXALIPLATIN TREATMENT NEEDS TO BE EXPLORED IN FUTURE RESEARCH. CONCLUSIONS: THESE FINDINGS SUGGEST THAT REDUCTION OF SIRT1-MEDIATED EPIGENETIC UPREGULATION OF NAV1.7 IN THE DRG CONTRIBUTES TO THE DEVELOPMENT OF OXALIPLATIN-INDUCED NEUROPATHIC PAIN IN RATS. THE INTRATHECAL DRUG DELIVERY TREATMENT OF ACTIVATING SIRT1 MIGHT BE A NOVEL THERAPEUTIC OPTION FOR OXALIPLATIN-INDUCED NEUROPATHIC PAIN. 2023 15 4913 25 PAIN MODULATION IN WAG/RIJ EPILEPTIC RATS (A GENETIC MODEL OF ABSENCE EPILEPSY): EFFECTS OF BIOLOGICAL AND PHARMACOLOGICAL HISTONE DEACETYLASE INHIBITORS. EPIGENETIC MECHANISMS ARE INVOLVED IN EPILEPSY AND CHRONIC PAIN DEVELOPMENT. ABOUT THAT, WE STUDIED THE EFFECTS OF THE NATURAL HISTONE DEACETYLASE (HDAC) INHIBITOR SODIUM BUTYRATE (BUT) IN COMPARISON WITH VALPROIC ACID (VPA) IN A VALIDATED GENETIC MODEL OF GENERALIZED ABSENCE EPILEPSY AND EPILEPTOGENESIS. WAG/RIJ RATS WERE TREATED WITH BUT (30 MG/KG), VPA (300 MG/KG), AND THEIR COMBINATION (BUT + VPA) DAILY PER OS FOR 6 MONTHS. RATS WERE SUBJECTED AT RANDALL-SELITTO, VON FREY, HOT PLATE, AND TAIL FLICK TESTS AFTER 1, 3, AND 6 MONTHS OF TREATMENT TO EVALUATE HYPERSENSITIVITY TO NOXIOUS AND NON-NOXIUOUS STIMULI. MOREOVER, PPAR-GAMMA (G3335 1 MG/KG), GABA-B (CGP35348 80 MG/KG), AND OPIOID (NALOXONE 1 MG/KG) RECEPTOR ANTAGONISTS WERE ADMINISTRATED TO INVESTIGATE THE POSSIBLE MECHANISMS INVOLVED IN ANALGESIC ACTIVITY. THE EXPRESSION OF NFKB, GLUTATHIONE REDUCTASE, AND PROTEIN OXIDATION (CARBONYLATION) WAS ALSO EVALUATED BY WESTERN BLOT ANALYSIS. WAG/RIJ RATS SHOWED AN ALTERED PAIN THRESHOLD THROUGHOUT THE STUDY (P < 0.001). BUT AND BUT + VPA TREATMENT REDUCED HYPERSENSITIVITY (P < 0.01). VPA WAS SIGNIFICANTLY EFFECTIVE ONLY AFTER 1 MONTH (P < 0.01). ALL THE THREE RECEPTORS ARE INVOLVED IN BUT + VPA EFFECTS (P < 0.001). BUT AND BUT + VPA DECREASED THE EXPRESSION OF NFKB AND ENHANCED GLUTATHIONE REDUCTASE (P < 0.01); PROTEIN OXIDATION (CARBONYLATION) WAS REDUCED (P < 0.01). NO EFFECT WAS REPORTED WITH VPA. IN CONCLUSION BUT, ALONE OR IN COADMINISTRATION WITH VPA, IS A VALUABLE CANDIDATE FOR MANAGING THE EPILEPSY-RELATED PERSISTENT PAIN. 2020 16 6612 23 ULTRA-LOW-DOSE NALOXONE ENHANCES THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN PTX-TREATED RATS: REGULATION ON GLOBAL HISTONE METHYLATION. OBJECTIVE: EPIGENETIC REPROGRAMMING MAY HAVE A POSSIBLE ROLE IN NEUROPATHIC PAIN DEVELOPMENT; THE PRESENT STUDY EXAMINED THE GLOBAL PATTERNS OF LYSINE HISTONE MODIFICATION. IN THIS SERIAL STUDY WE ANALYZED THE LEVELS OF HISTONE 3 LYSINE 4 MONOMETHYLATION, HISTONE 3 LYSINE 4 DIMETHYLATION, AND HISTONE 3 LYSINE 9 TRIMETHYLATION IN PERTUSSIS TOXIN (PTX)-INDUCED THERMAL HYPERALGESIC RAT SPINAL CORDS. METHODS: MALE WISTAR RATS IMPLANTED WITH AN INTRATHECAL CATHETER RECEIVED A SINGLE INTRATHECAL PTX (1 MUG IN 5 MUL SALINE) INJECTION. FOUR DAYS LATER, THEY WERE RANDOMLY ASSIGNED TO RECEIVE EITHER A SINGLE INJECTION OF SALINE, OR ULTRA-LOW-DOSE NALOXONE (15 NG IN 5 MUL SALINE), FOLLOWED BY MORPHINE (10 MUG IN 5 MUL SALINE) INJECTION 30 MINUTES LATER. RESULTS: THE RESULTS SHOWED THAT PTX INJECTION INDUCED THERMAL HYPERALGESIA AND SIGNIFICANT INCREASE OF GLOBAL HISTONE METHYLATION IN THE SPINAL CORDS. INTRATHECAL MORPHINE ALONE DID NOT AFFECT THE THERMAL HYPERALGESIA AND GLOBAL HISTONE METHYLATION. IN CONTRAST, INTRATHECAL ADMINISTRATION OF ULTRA-LOW-DOSE NALOXONE PLUS MORPHINE SIGNIFICANTLY ATTENUATED THE PTX-INDUCED THERMAL HYPERALGESIA AND DOWN-REGULATED THE GLOBAL HISTONE METHYLATION. CONCLUSION: THE RESULTS SUGGEST THAT ULTRA-LOW-DOSE NALOXONE MIGHT BE CLINICAL VALUABLE FOR NEUROPATHIC PAIN MANAGEMENT VIA REGULATING GLOBAL HISTONE MODIFICATION. 2012 17 2363 27 EPIGENETIC REGULATION OF SPINAL CORD GENE EXPRESSION CONTRIBUTES TO ENHANCED POSTOPERATIVE PAIN AND ANALGESIC TOLERANCE SUBSEQUENT TO CONTINUOUS OPIOID EXPOSURE. BACKGROUND: OPIOIDS HAVE BECOME THE MAINSTAY FOR TREATMENT OF MODERATE TO SEVERE PAIN AND ARE COMMONLY USED TO TREAT SURGICAL PAIN. WHILE OPIOID ADMINISTRATION HAS BEEN SHOWN TO CAUSE OPIOID-INDUCED HYPERALGESIA AND TOLERANCE, INTERACTIONS BETWEEN OPIOID ADMINISTRATION AND SURGERY WITH RESPECT TO THESE PROBLEMATIC ADAPTATIONS HAVE SCARCELY BEEN ADDRESSED. ACCUMULATING EVIDENCE SUGGESTS OPIOIDS AND NOCICEPTIVE SIGNALING MAY CONVERGE ON EPIGENETIC MECHANISMS IN SPINAL CORD TO ENHANCE OR PROLONG NEUROPLASTIC CHANGES. EPIGENETIC REGULATION OF BDNF (BRAIN-DERIVED NEUROTROPHIC FACTOR) AND PDYN (PRODYNORPHIN) GENES MAY BE INVOLVED. RESULTS: FOUR DAYS OF ASCENDING DOSES OF MORPHINE TREATMENT CAUSED OPIOID-INDUCED HYPERALGESIA AND REDUCED OPIOID ANALGESIC EFFICACY IN MICE. BOTH OPIOID-INDUCED HYPERALGESIA AND THE REDUCED OPIOID ANALGESIC EFFICACY WERE ENHANCED IN MICE THAT RECEIVED HINDPAW INCISIONS. THE EXPRESSION OF BDNF AND PDYN (QPCR) WAS INCREASED AFTER MORPHINE TREATMENT AND INCISION. CHROMATIN IMMUNOPRECIPITATION ASSAYS DEMONSTRATED THAT THE PDYN AND BDNF PROMOTERS WERE MORE STRONGLY ASSOCIATED WITH ACETYLATED H3K9 AFTER MORPHINE PLUS INCISION THAN IN THE MORPHINE OR INCISION ALONE GROUPS. SELECTIVE TROPOMYOSIN-RELATED KINASE B (ANA-12) AND KAPPA-OPIOID RECEPTOR (NOR-BINALTORPHIMINE) ANTAGONISTS WERE ADMINISTERED INTRATHECALLY, BOTH REDUCED HYPERALGESIA ONE OR THREE DAYS AFTER SURGERY. ADMINISTRATION OF ANA-12 OR NOR-BINALTORPHIMINE ATTENUATED THE DECREASED MORPHINE ANALGESIC EFFICACY ON DAY 1, BUT ONLY NOR-BINALTORPHIMINE WAS EFFECTIVE ON DAY 3 AFTER INCISION IN OPIOID-EXPOSED GROUP. COADMINISTRATION OF HISTONE ACETYLTRANSFERASE INHIBITOR ANACARDIC ACID DAILY WITH MORPHINE BLOCKED THE DEVELOPMENT OF OPIOID-INDUCED HYPERALGESIA AND ATTENUATED INCISION-ENHANCED HYPERALGESIA IN MORPHINE-TREATED MICE. ANACARDIC ACID HAD SIMILAR EFFECTS ON ANALGESIC TOLERANCE, SHOWING THE INVOLVEMENT OF HISTONE ACETYLATION IN THE INTERACTIONS DETECTED. CONCLUSIONS: SPINAL EPIGENETIC CHANGES INVOLVING BDNF AND PDYN MAY CONTRIBUTE TO THE ENHANCED POSTOPERATIVE NOCICEPTIVE SENSITIZATION AND ANALGESIC TOLERANCE OBSERVED AFTER CONTINUOUS OPIOID EXPOSURE. TREATMENTS BLOCKING THE EPIGENETICALLY MEDIATED UP-REGULATION OF THESE GENES OR ADMINISTRATION OF TRKB OR KAPPA-OPIOID RECEPTOR ANTAGONISTS MAY IMPROVE THE CLINICAL UTILITY OF OPIOIDS, PARTICULARLY AFTER SURGERY. 2016 18 4275 32 MICROGLIA ACTIVATION IN THE MIDBRAIN OF THE HUMAN NEONATE: THE EFFECT OF PERINATAL HYPOXIC-ISCHEMIC INJURY. PERINATAL HYPOXIA-ISCHEMIA (PHI) IS A MAJOR RISK FACTOR FOR THE DEVELOPMENT OF NEUROPSYCHIATRIC DEFICITS LATER IN LIFE. WE PREVIOUSLY REPORTED THAT AFTER PROLONGED PHI, THE DOPAMINERGIC NEURONS OF THE HUMAN NEONATE SHOWED A DRAMATIC REDUCTION OF TYROSINE HYDROXYLASE (TH) IN THE SUBSTANTIA NIGRA, WITHOUT IMPORTANT SIGNS OF NEURONAL DEGENERATION DESPITE THE SIGNIFICANT REDUCTION IN THEIR CELL SIZE. SINCE MICROGLIA ACTIVATION COULD PRECEDE NEURONAL DEATH, WE NOW INVESTIGATED 2 MICROGLIA ACTIVATION MARKERS, IONIZED CALCIUM-BINDING ADAPTER MOLECULE 1 (IBA1), AND THE PHAGOCYTOSIS MARKER CD68. THE HIGHEST IBA1 IMMUNOREACTIVITY WAS FOUND IN NEONATES WITH NEUROPATHOLOGICAL LESIONS OF SEVERE/ABRUPT PHI, WHILE THE LOWEST IN SUBJECTS WITH MODERATE/PROLONGED OR OLDER PHI. SUBJECTS WITH VERY SEVERE/PROLONGED OR CHRONIC PHI SHOWED AN INCREASED IBA1 EXPRESSION AND VERY ACTIVATED MICROGLIAL MORPHOLOGY. HEAVY ATTACHMENT OF MICROGLIA ON TH NEURONS AND REMARKABLE EXPRESSION OF CD68 WERE ALSO OBSERVED INDICATING PHAGOCYTOSIS IN THIS GROUP. FEMALES APPEAR TO EXPRESS MORE IBA1 THAN MALES, SUGGESTING A GENDER DIFFERENCE IN MICROGLIA MATURATION AND IMMUNE REACTIVITY AFTER PHI INSULT. PHI-INDUCED MICROGLIAL "PRIMING" DURING THE SENSITIVE FOR BRAIN DEVELOPMENT PERINATAL/NEONATAL PERIOD, IN COMBINATION WITH GENETIC OR OTHER EPIGENETIC FACTORS, COULD PREDISPOSE THE SURVIVORS TO NEUROPSYCHIATRIC DISORDERS LATER IN LIFE, POSSIBLY THROUGH A SEXUALLY DIMORPHIC WAY. 2022 19 1800 20 EFFECT OF HISTONE DEACETYLASE INHIBITOR ON ETHANOL WITHDRAWAL-INDUCED HYPERALGESIA IN RATS. BACKGROUND: INCREASED PAIN SENSITIVITY IS OBSERVED FOLLOWING ALCOHOL WITHDRAWAL, AND ATTEMPTS TO ALLEVIATE THIS HYPERALGESIA CAN CONTRIBUTE TO THE CYCLE OF ADDICTION. THE AIM OF THIS STUDY WAS TO DETERMINE IF ALCOHOL WITHDRAWAL-INDUCED HYPERALGESIA WAS OBSERVED IN A CHRONIC ETHANOL EXPOSURE MODEL AND IF THIS PAIN WAS AFFECTED BY HISTONE DEACETYLASE INHIBITORS, THUS REVEALING AN EPIGENETIC MECHANISM. METHODS: ADULT MALE SPRAGUE DAWLEY RATS RECEIVED LIEBER-DECARLI LIQUID CONTROL OR ETHANOL (9% V/V) DIET FOR 15 DAYS. MECHANICAL SENSITIVITY WAS MEASURED WITH VON FREY HAIR STIMULATION OF THE HINDPAW DURING ETHANOL ADMINISTRATION AND 24- AND 72-HOUR WITHDRAWAL. RESULTS: ETHANOL WITHDRAWAL PRODUCED SEVERE AND SUSTAINED MECHANICAL HYPERALGESIA, AN EFFECT NOT OBSERVED IN THE CONTROL OR ETHANOL-MAINTAINED GROUPS. FURTHERMORE, THIS HYPERALGESIA WAS ATTENUATED BY THE HISTONE DEACETYLASE INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID TREATMENT. CONCLUSIONS: HEIGHTENED PAIN SENSITIVITY WAS OBSERVED FOLLOWING WITHDRAWAL FROM CHRONIC ETHANOL EXPOSURE, AND HISTONE DEACETYLASE INHIBITORS COULD BE NOVEL TREATMENTS FOR THIS ALCOHOL WITHDRAWAL-INDUCED HYPERALGESIA. 2019 20 1120 22 COMPARISON OF DIFFERENT HISTONE DEACETYLASE INHIBITORS IN ATTENUATING INFLAMMATORY PAIN IN RATS. HISTONE DEACETYLASE INHIBITORS (HDACIS), WHICH INTERFERE WITH THE EPIGENETIC PROCESS OF HISTONE ACETYLATION, HAVE SHOWN ANALGESIC EFFECTS IN ANIMAL MODELS OF PERSISTENT PAIN. THE HDAC FAMILY COMPRISES 18 GENES; HOWEVER, THE DIFFERENT EFFECTS OF DISTINCT CLASSES OF HDACIS ON PAIN RELIEF REMAIN UNCLEAR. THE AIM OF THIS STUDY WAS TO DETERMINE THE EFFICACY OF THESE HDACIS ON ATTENUATING THERMAL HYPERALGESIA IN PERSISTENT INFLAMMATORY PAIN. PERSISTENT INFLAMMATORY PAIN WAS INDUCED BY INJECTING COMPLETE FREUND'S ADJUVANT (CFA) INTO THE LEFT HIND PAW OF RATS. THEN, HDACIS TARGETING CLASS I (ENTINOSTAT (MS-275)) AND CLASS IIA (SODIUM BUTYRATE, VALPROIC ACID (VPA), AND 4-PHENYLBUTYRIC ACID (4-PBA)), OR CLASS II (SUBEROYLANILIDE HYDOXAMIC ACID (SAHA), TRICHOSTATIN A (TSA), AND DACINOSTAT (LAQ824)) WERE ADMINISTERED INTRAPERITONEALLY ONCE DAILY FOR 3 OR 4 DAYS. WE FOUND THAT THE INJECTION OF SAHA ONCE A DAY FOR 3 DAYS SIGNIFICANTLY ATTENUATED CFA-INDUCED THERMAL HYPERALGESIA FROM DAY 4 AND LASTED 7 DAYS. IN COMPARISON WITH SAHA, SUPPRESSION OF HYPERALGESIA BY 4-PBA PEAKED ON DAY 2, WHEREAS THAT BY MS-275 OCCURRED ON DAYS 5 AND 6. FATIGUE WAS A SERIOUS SIDE EFFECT SEEN WITH MS-275. THESE FINDINGS WILL BE BENEFICIAL FOR OPTIMIZING THE SELECTION OF SPECIFIC HDACIS IN MEDICAL FIELDS SUCH AS PAIN MEDICINE AND NEUROPSYCHIATRY. 2019