1 6023 139 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 2 2113 35 EPIGENETIC HALLMARKS OF AGE-RELATED MACULAR DEGENERATION ARE RECAPITULATED IN A PHOTOSENSITIVE MOUSE MODEL. AGE-RELATED MACULAR DEGENERATION (AMD) IS A CHRONIC, MULTIFACTORIAL DISORDER AND A LEADING CAUSE OF BLINDNESS IN THE ELDERLY. CHARACTERIZED BY PROGRESSIVE PHOTORECEPTOR DEGENERATION IN THE CENTRAL RETINA, DISEASE PROGRESSION INVOLVES EPIGENETIC CHANGES IN CHROMATIN ACCESSIBILITY RESULTING FROM ENVIRONMENTAL EXPOSURES AND CHRONIC STRESS. HERE, WE REPORT THAT A PHOTOSENSITIVE MOUSE MODEL OF ACUTE STRESS-INDUCED PHOTORECEPTOR DEGENERATION RECAPITULATES THE EPIGENETIC HALLMARKS OF HUMAN AMD. GLOBAL EPIGENOMIC PROFILING WAS ACCOMPLISHED BY EMPLOYING AN ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN USING SEQUENCING (ATAC-SEQ), WHICH REVEALED AN ASSOCIATION BETWEEN DECREASED CHROMATIN ACCESSIBILITY AND STRESS-INDUCED PHOTORECEPTOR CELL DEATH IN OUR MOUSE MODEL. THE EPIGENOMIC CHANGES INDUCED BY LIGHT DAMAGE INCLUDE REDUCED EUCHROMATIN AND INCREASED HETEROCHROMATIN ABUNDANCE, RESULTING IN TRANSCRIPTIONAL AND TRANSLATIONAL DYSREGULATION THAT ULTIMATELY DRIVES PHOTORECEPTOR APOPTOSIS AND AN INFLAMMATORY REACTIVE GLIOSIS IN THE RETINA. OF PARTICULAR INTEREST, PHARMACOLOGICAL INHIBITION OF HISTONE DEACETYLASE 11 (HDAC11) AND SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 2 (SUV39H2), KEY HISTONE-MODIFYING ENZYMES INVOLVED IN PROMOTING REDUCED CHROMATIN ACCESSIBILITY, AMELIORATED LIGHT DAMAGE IN OUR MOUSE MODEL, SUPPORTING A CAUSAL LINK BETWEEN DECREASED CHROMATIN ACCESSIBILITY AND PHOTORECEPTOR DEGENERATION, THEREBY ELUCIDATING A POTENTIAL NEW THERAPEUTIC STRATEGY TO COMBAT AMD. 2020 3 6489 26 TRACHOMA AND OCULAR CHLAMYDIAL INFECTION IN THE ERA OF GENOMICS. TRACHOMA IS A BLINDING DISEASE USUALLY CAUSED BY INFECTION WITH CHLAMYDIA TRACHOMATIS (CT) SEROVARS A, B, AND C IN THE UPPER TARSAL CONJUNCTIVA. INDIVIDUALS IN ENDEMIC REGIONS ARE REPEATEDLY INFECTED WITH CT THROUGHOUT CHILDHOOD. A PROPORTION OF INDIVIDUALS EXPERIENCE PROLONGED OR SEVERE INFLAMMATORY EPISODES THAT ARE KNOWN TO BE SIGNIFICANT RISK FACTORS FOR OCULAR SCARRING IN LATER LIFE. CONTINUED SCARRING OFTEN LEADS TO TRICHIASIS AND IN-TURNING OF THE EYELASHES, WHICH CAUSES PAIN AND CAN EVENTUALLY CAUSE BLINDNESS. THE MECHANISMS DRIVING THE CHRONIC IMMUNOPATHOLOGY IN THE CONJUNCTIVA, WHICH LARGELY PROGRESSES IN THE ABSENCE OF DETECTABLE CT INFECTION IN ADULTS, ARE LIKELY TO BE MULTIFACTORIAL. SOCIOECONOMIC STATUS, EDUCATION, AND BEHAVIOR HAVE BEEN IDENTIFIED AS CONTRIBUTING TO THE RISK OF SCARRING AND INFLAMMATION. WE FOCUS ON THE CONTRIBUTION OF HOST AND PATHOGEN GENETIC VARIATION, BACTERIAL ECOLOGY OF THE CONJUNCTIVA, AND HOST EPIGENETIC IMPRINTING INCLUDING SMALL RNA REGULATION BY BOTH HOST AND PATHOGEN IN THE DEVELOPMENT OF OCULAR PATHOLOGY. EACH OF THESE FACTORS OR PROCESSES CONTRIBUTES TO PATHOGENIC OUTCOMES IN OTHER INFLAMMATORY DISEASES AND WE OUTLINE THEIR POTENTIAL ROLE IN TRACHOMA. 2015 4 2206 23 EPIGENETIC MODIFICATIONS AND DIABETIC RETINOPATHY. DIABETIC RETINOPATHY REMAINS ONE OF THE MOST DEBILITATING CHRONIC COMPLICATIONS, BUT DESPITE EXTENSIVE RESEARCH IN THE FIELD, THE EXACT MECHANISM(S) RESPONSIBLE FOR HOW RETINA IS DAMAGED IN DIABETES REMAINS AMBIGUOUS. MANY METABOLIC PATHWAYS HAVE BEEN IMPLICATED IN ITS DEVELOPMENT, AND GENES ASSOCIATED WITH THESE PATHWAYS ARE ALTERED. DIABETIC ENVIRONMENT ALSO FACILITATES EPIGENETICS MODIFICATIONS, WHICH CAN ALTER THE GENE EXPRESSION WITHOUT PERMANENT CHANGES IN DNA SEQUENCE. THE ROLE OF EPIGENETICS IN DIABETIC RETINOPATHY IS NOW AN EMERGING AREA, AND RECENT WORK HAS SHOWN THAT GENES ENCODING MITOCHONDRIAL SUPEROXIDE DISMUTASE (SOD2) AND MATRIX METALLOPROTEINASE-9 (MMP-9) ARE EPIGENETICALLY MODIFIED, ACTIVATES OF EPIGENETIC MODIFICATION ENZYMES, HISTONE LYSINE DEMETHYLASE 1 (LSD1), AND DNA METHYLTRANSFERASE ARE INCREASED, AND THE MICRO RNAS RESPONSIBLE FOR REGULATING NUCLEAR TRANSCRIPTIONAL FACTOR AND VEGF ARE UPREGULATED. WITH THE GROWING EVIDENCE OF EPIGENETIC MODIFICATIONS IN DIABETIC RETINOPATHY, BETTER UNDERSTANDING OF THESE MODIFICATIONS HAS POTENTIAL TO IDENTIFY NOVEL TARGETS TO INHIBIT THIS DEVASTATING DISEASE. FORTUNATELY, THE INHIBITORS AND MIMICS TARGETED TOWARDS HISTONE MODIFICATION, DNA METHYLATION, AND MIRNAS ARE NOW BEING TRIED FOR CANCER AND OTHER CHRONIC DISEASES, AND BETTER UNDERSTANDING OF THE ROLE OF EPIGENETICS IN DIABETIC RETINOPATHY WILL OPEN THE DOOR FOR THEIR POSSIBLE USE IN COMBATING THIS BLINDING DISEASE. 2013 5 6567 33 TRANSLATOMIC RESPONSE OF RETINAL MULLER GLIA TO ACUTE AND CHRONIC STRESS. ANALYSIS OF RETINA CELL TYPE-SPECIFIC EPIGENETIC AND TRANSCRIPTOMIC SIGNATURES IS CRUCIAL TO UNDERSTANDING THE PATHOPHYSIOLOGY OF RETINAL DEGENERATIONS SUCH AS AGE-RELATED MACULAR DEGENERATION (AMD) AND DELINEATING CELL AUTONOMOUS AND CELL-NON-AUTONOMOUS MECHANISMS. WE HAVE DISCOVERED THAT ALDH1L1 IS SPECIFICALLY EXPRESSED IN THE MAJOR MACROGLIA OF THE RETINA, MULLER GLIA, AND, UNLIKE THE BRAIN, IS NOT EXPRESSED IN RETINAL ASTROCYTES. THIS ALLOWS USE OF ALDH1L1 CRE DRIVERS AND NUCLEAR TAGGING AND TRANSLATING RIBOSOME AFFINITY PURIFICATION (NUTRAP) CONSTRUCTS FOR TEMPORALLY CONTROLLED LABELING AND PAIRED ANALYSIS OF MULLER GLIA EPIGENOMES AND TRANSLATOMES. AS VALIDATED THROUGH A VARIETY OF APPROACHES, THE ALDH1L1CRE/ERT2-NUTRAP MODEL PROVIDES MULLER GLIA SPECIFIC TRANSLATOMIC AND EPIGENOMIC PROFILES WITHOUT THE NEED TO ISOLATE WHOLE CELLS. APPLICATION OF THIS APPROACH TO MODELS OF ACUTE INJURY (OPTIC NERVE CRUSH) AND CHRONIC STRESS (AGING) UNCOVERED FEW COMMON MULLER GLIA-SPECIFIC TRANSCRIPTOME CHANGES IN INFLAMMATORY PATHWAYS, AND MOSTLY DIFFERENTIAL SIGNATURES FOR EACH STIMULUS. THE EXPRESSION OF MEMBERS OF THE IL-6 AND INTEGRIN-LINKED KINASE SIGNALING PATHWAYS WAS ENHANCED IN MULLER GLIA IN RESPONSE TO OPTIC NERVE CRUSH BUT NOT AGING. UNIQUE CHANGES IN NEUROINFLAMMATION AND FIBROSIS SIGNALING PATHWAYS WERE OBSERVED IN RESPONSE TO AGING BUT NOT WITH OPTIC NERVE CRUSH. THE ALDH1L1CRE/ERT2-NUTRAP MODEL ALLOWS FOCUSED MOLECULAR ANALYSES OF A SINGLE, MINORITY CELL TYPE WITHIN THE RETINA, PROVIDING MORE SUBSTANTIAL EFFECT SIZES THAN WHOLE TISSUE ANALYSES. THE NUTRAP MODEL, NUCLEIC ACID ISOLATION, AND VALIDATION APPROACHES PRESENTED HERE CAN BE APPLIED TO ANY RETINA CELL TYPE FOR WHICH A CELL TYPE-SPECIFIC CRE IS AVAILABLE. 2022 6 6443 37 THERAPEUTIC APPROACHES TO HISTONE REPROGRAMMING IN RETINAL DEGENERATION. RECENT DATA HAVE REVEALED EPIGENETIC DERANGEMENTS AND SUBSEQUENT CHROMATIN REMODELING AS A POTENT BIOLOGIC SWITCH FOR CHRONIC INFLAMMATION AND CELL SURVIVAL WHICH ARE IMPORTANT THERAPEUTIC TARGETS IN THE PATHOGENESIS OF SEVERAL RETINAL DEGENERATIONS. HISTONE DEACETYLASES (HDACS) ARE A MAJOR COMPONENT OF THIS SYSTEM AND SERVE AS A UNIQUE CONTROL OF THE CHROMATIN REMODELING PROCESS. WITH A MULTITUDE OF TARGETED HDAC INHIBITORS NOW AVAILABLE, THEIR USE IN BOTH BASIC SCIENCE AND CLINICAL STUDIES HAS WIDENED SUBSTANTIALLY. IN THE FIELD OF OCULAR BIOLOGY, THERE ARE DATA TO SUGGEST THAT HDAC INHIBITION MAY SUPPRESS NEOVASCULARIZATION AND MAY BE A POSSIBLE TREATMENT FOR RETINITIS PIGMENTOSA AND DRY AGE-RELATED MACULAR DEGENERATION (AMD). HOWEVER, THE EFFECTS OF THESE INHIBITORS ON CELL SURVIVAL AND CHEMOKINE EXPRESSION IN THE CHORIORETINAL TISSUES REMAIN VERY UNCLEAR. HERE, WE REVIEW THE MULTIFACETED BIOLOGY OF HDAC ACTIVITY AND PHARMACOLOGIC INHIBITION WHILE OFFERING FURTHER INSIGHT INTO THE IMPORTANCE OF THIS EPIGENETIC PATHWAY IN RETINAL DEGENERATIONS. OUR LABORATORY INVESTIGATIONS AIM TO OPEN TRANSLATIONAL AVENUES TO ADVANCE DRY AMD THERAPEUTICS WHILE EXPLORING THE ROLE OF ACETYLATION ON INFLAMMATORY GENE EXPRESSION IN THE AGING AND DEGENERATING RETINA. 2016 7 5803 30 STING SIGNALING ACTIVATION INHIBITS HBV REPLICATION AND ATTENUATES THE SEVERITY OF LIVER INJURY AND HBV-INDUCED FIBROSIS. THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) OF HBV PLAYS A CRUCIAL ROLE IN VIRAL PERSISTENCE AND IS ALSO A RISK FACTOR FOR DEVELOPING HBV-INDUCED DISEASES, INCLUDING LIVER FIBROSIS. STIMULATOR OF INTERFERON GENES (STING), A MASTER REGULATOR OF DNA-MEDIATED INNATE IMMUNE ACTIVATION, IS A POTENTIAL THERAPEUTIC TARGET FOR VIRAL INFECTION AND VIRUS-RELATED DISEASES. IN THIS STUDY, AGONIST-INDUCED STING SIGNALING ACTIVATION IN MACROPHAGES WAS REVEALED TO INHIBIT CCCDNA-MEDIATED TRANSCRIPTION AND HBV REPLICATION VIA EPIGENETIC MODIFICATION IN HEPATOCYTES. NOTABLY, STING ACTIVATION COULD EFFICIENTLY ATTENUATE THE SEVERITY OF LIVER INJURY AND FIBROSIS IN A CHRONIC RECOMBINANT CCCDNA (RCCCDNA) MOUSE MODEL, WHICH IS A PROVEN SUITABLE RESEARCH PLATFORM FOR HBV-INDUCED FIBROSIS. MECHANISTICALLY, STING-ACTIVATED AUTOPHAGIC FLUX COULD SUPPRESS MACROPHAGE INFLAMMASOME ACTIVATION, LEADING TO THE AMELIORATION OF LIVER INJURY AND HBV-INDUCED FIBROSIS. OVERALL, THE ACTIVATION OF STING SIGNALING COULD INHIBIT HBV REPLICATION THROUGH EPIGENETIC SUPPRESSION OF CCCDNA AND ALLEVIATE HBV-INDUCED LIVER FIBROSIS THROUGH THE SUPPRESSION OF MACROPHAGE INFLAMMASOME ACTIVATION BY ACTIVATING AUTOPHAGIC FLUX IN A CHRONIC HBV MOUSE MODEL. THIS STUDY SUGGESTS THAT TARGETING THE STING SIGNALING PATHWAY MAY BE AN IMPORTANT THERAPEUTIC STRATEGY TO PROTECT AGAINST PERSISTENT HBV REPLICATION AND HBV-INDUCED FIBROSIS. 2022 8 4582 37 N-TERMINAL BET BROMODOMAIN INHIBITORS DISRUPT A BRD4-P65 INTERACTION AND REDUCE INDUCIBLE NITRIC OXIDE SYNTHASE TRANSCRIPTION IN PANCREATIC BETA-CELLS. CHRONIC INFLAMMATION OF PANCREATIC ISLETS IS A KEY DRIVER OF BETA-CELL DAMAGE THAT CAN LEAD TO AUTOREACTIVITY AND THE EVENTUAL ONSET OF AUTOIMMUNE DIABETES (T1D). IN THE ISLET, ELEVATED LEVELS OF PROINFLAMMATORY CYTOKINES INDUCE THE TRANSCRIPTION OF THE INDUCIBLE NITRIC OXIDE SYNTHASE (INOS) GENE, NOS2, ULTIMATELY RESULTING IN INCREASED NITRIC OXIDE (NO). EXCESSIVE OR PROLONGED EXPOSURE TO NO CAUSES BETA-CELL DYSFUNCTION AND FAILURE ASSOCIATED WITH DEFECTS IN MITOCHONDRIAL RESPIRATION. RECENT STUDIES SHOWED THAT INHIBITION OF THE BROMODOMAIN AND EXTRATERMINAL DOMAIN (BET) FAMILY OF PROTEINS, A DRUGGABLE CLASS OF EPIGENETIC READER PROTEINS, PREVENTS THE ONSET AND PROGRESSION OF T1D IN THE NON-OBESE DIABETIC MOUSE MODEL. WE HYPOTHESIZED THAT BET PROTEINS CO-ACTIVATE TRANSCRIPTION OF CYTOKINE-INDUCED INFLAMMATORY GENE TARGETS IN BETA-CELLS AND THAT SELECTIVE, CHEMOTHERAPEUTIC INHIBITION OF BET BROMODOMAINS COULD REDUCE SUCH TRANSCRIPTION. HERE, WE INVESTIGATED THE ABILITY OF BET BROMODOMAIN SMALL MOLECULE INHIBITORS TO REDUCE THE BETA-CELL RESPONSE TO THE PROINFLAMMATORY CYTOKINE INTERLEUKIN 1 BETA (IL-1BETA). BET BROMODOMAIN INHIBITION ATTENUATED IL-1BETA-INDUCED TRANSCRIPTION OF THE INFLAMMATORY MEDIATOR NOS2 AND CONSEQUENT INOS PROTEIN AND NO PRODUCTION. REDUCED NOS2 TRANSCRIPTION IS CONSISTENT WITH INHIBITION OF NF-KAPPAB FACILITATED BY DISRUPTING THE INTERACTION OF A SINGLE BET FAMILY MEMBER, BRD4, WITH THE NF-KAPPAB SUBUNIT, P65. USING RECENTLY REPORTED SELECTIVE INHIBITORS OF THE FIRST AND SECOND BET BROMODOMAINS, INHIBITION OF ONLY THE FIRST BROMODOMAIN WAS NECESSARY TO REDUCE THE INTERACTION OF BRD4 WITH P65 IN BETA-CELLS. MOREOVER, INHIBITION OF THE FIRST BROMODOMAIN WAS SUFFICIENT TO MITIGATE IL-1BETA-DRIVEN DECREASES IN MITOCHONDRIAL OXYGEN CONSUMPTION RATES AND BETA-CELL VIABILITY. BY IDENTIFYING A ROLE FOR THE INTERACTION BETWEEN BRD4 AND P65 IN CONTROLLING THE RESPONSE OF BETA-CELLS TO PROINFLAMMATORY CYTOKINES, WE PROVIDE MECHANISTIC INFORMATION ON HOW BET BROMODOMAIN INHIBITION CAN DECREASE INFLAMMATION. THESE STUDIES ALSO SUPPORT THE POTENTIAL THERAPEUTIC APPLICATION OF MORE SELECTIVE BET BROMODOMAIN INHIBITORS IN ATTENUATING BETA-CELL INFLAMMATION. 2022 9 593 47 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 10 697 36 BROMODOMAIN AND EXTRATERMINAL PROTEINS AS NOVEL EPIGENETIC TARGETS FOR RENAL DISEASES. EPIGENETIC MECHANISMS, ESPECIALLY DNA METHYLATION AND HISTONE MODIFICATIONS, ARE DYNAMIC PROCESSES THAT REGULATE THE GENE EXPRESSION TRANSCRIPTIONAL PROGRAM IN NORMAL AND DISEASED STATES. THE BROMODOMAIN AND EXTRATERMINAL (BET) PROTEIN FAMILY (BRD2, BRD3, BRD4, AND BRDT) ARE EPIGENETIC READERS THAT, VIA BROMODOMAINS, REGULATE GENE TRANSCRIPTION BY BINDING TO ACETYLATED LYSINE RESIDUES ON HISTONES AND MASTER TRANSCRIPTIONAL FACTORS. EXPERIMENTAL DATA HAVE DEMONSTRATED THE INVOLVEMENT OF SOME BET PROTEINS IN MANY PATHOLOGICAL CONDITIONS, INCLUDING TUMOR DEVELOPMENT, INFECTIONS, AUTOIMMUNITY, AND INFLAMMATION. SELECTIVE BROMODOMAIN INHIBITORS ARE EPIGENETIC DRUGS THAT BLOCK THE INTERACTION BETWEEN BET PROTEINS AND ACETYLATED PROTEINS, THUS EXERTING BENEFICIAL EFFECTS. RECENT DATA HAVE DESCRIBED THE BENEFICIAL EFFECT OF BET INHIBITION ON EXPERIMENTAL RENAL DISEASES. EMERGING EVIDENCE UNDERSCORES THE IMPORTANCE OF ENVIRONMENTAL MODIFICATIONS IN THE ORIGIN OF PATHOLOGICAL FEATURES IN CHRONIC KIDNEY DISEASES (CKD). SEVERAL CELLULAR PROCESSES SUCH AS OXIDATION, METABOLIC DISORDERS, CYTOKINES, INFLAMMATION, OR ACCUMULATED UREMIC TOXINS MAY INDUCE EPIGENETIC MODIFICATIONS THAT REGULATE KEY PROCESSES INVOLVED IN RENAL DAMAGE AND IN OTHER PATHOLOGICAL CONDITIONS OBSERVED IN CKD PATIENTS. HERE, WE REVIEW HOW TARGETING BROMODOMAINS IN BET PROTEINS MAY REGULATE ESSENTIAL PROCESSES INVOLVED IN RENAL DISEASES AND IN ASSOCIATED COMPLICATIONS FOUND IN CKD PATIENTS, SUCH AS CARDIOVASCULAR DAMAGE, HIGHLIGHTING THE POTENTIAL OF EPIGENETIC THERAPEUTIC STRATEGIES AGAINST BET PROTEINS FOR CKD TREATMENT AND ASSOCIATED RISKS. 2019 11 4106 31 MECHANISM OF INFLAMMATION IN AGE-RELATED MACULAR DEGENERATION. AGE-RELATED MACULAR DEGENERATION (AMD) IS A MULTIFACTORIAL DISEASE THAT REPRESENTS THE MOST COMMON CAUSE OF IRREVERSIBLE VISUAL IMPAIRMENT AMONG PEOPLE OVER THE AGE OF 50 IN EUROPE, THE UNITED STATES, AND AUSTRALIA, ACCOUNTING FOR UP TO 50% OF ALL CASES OF CENTRAL BLINDNESS. RISK FACTORS OF AMD ARE HETEROGENEOUS, MAINLY INCLUDING INCREASING AGE AND DIFFERENT GENETIC PREDISPOSITIONS, TOGETHER WITH SEVERAL ENVIRONMENTAL/EPIGENETIC FACTORS, THAT IS, CIGARETTE SMOKING, DIETARY HABITS, AND PHOTOTOXIC EXPOSURE. IN THE AGING RETINA, FREE RADICALS AND OXIDIZED LIPOPROTEINS ARE CONSIDERED TO BE MAJOR CAUSES OF TISSUE STRESS RESULTING IN LOCAL TRIGGERS FOR PARAINFLAMMATION, A CHRONIC STATUS WHICH CONTRIBUTES TO INITIATION AND/OR PROGRESSION OF MANY HUMAN NEURODEGENERATIVE DISEASES SUCH AS AMD. EXPERIMENTAL AND CLINICAL EVIDENCES STRONGLY INDICATE THE PATHOGENETIC ROLE OF IMMUNOLOGIC PROCESSES IN AMD OCCURRENCE, CONSISTING OF PRODUCTION OF INFLAMMATORY RELATED MOLECULES, RECRUITMENT OF MACROPHAGES, COMPLEMENT ACTIVATION, MICROGLIAL ACTIVATION AND ACCUMULATION WITHIN THOSE STRUCTURES THAT COMPOSE AN ESSENTIAL AREA OF THE RETINA KNOWN AS MACULA LUTEA. THIS PAPER REVIEWS SOME ATTRACTIVE ASPECTS OF THE LITERATURE ABOUT THE MECHANISMS OF INFLAMMATION IN AMD, ESPECIALLY FOCUSING ON THOSE FINDINGS OR ARGUMENTS MORE DIRECTLY TRANSLATABLE TO IMPROVE THE CLINICAL MANAGEMENT OF PATIENTS WITH AMD AND TO PREVENT THE SEVERE VISION LOSS CAUSED BY THIS DISEASE. 2012 12 3411 28 HP1GAMMA PREVENTS ACTIVATION OF THE CGAS/STING PATHWAY BY PRESERVING NUCLEAR ENVELOPE AND GENOMIC INTEGRITY IN COLON ADENOCARCINOMA CELLS. CHRONIC INFLAMMATORY PROCESSES IN THE INTESTINE RESULT IN SERIOUS CONDITIONS SUCH AS INFLAMMATORY BOWEL DISEASE (IBD) AND CANCER. AN INCREASED DETECTION OF CYTOPLASMIC DNA SENSORS HAS BEEN REPORTED IN THE IBD COLON MUCOSA, SUGGESTING THEIR CONTRIBUTION IN MUCOSAL INFLAMMATION. YET, THE MECHANISMS ALTERING DNA HOMEOSTASIS AND TRIGGERING THE ACTIVATION OF DNA SENSORS REMAIN POORLY UNDERSTOOD. IN THIS STUDY, WE SHOW THAT THE EPIGENETIC REGULATOR HP1GAMMA PLAYS A ROLE IN PRESERVING NUCLEAR ENVELOPE AND GENOMIC INTEGRITY IN ENTEROCYTIC CELLS, THEREBY PROTECTING AGAINST THE PRESENCE OF CYTOPLASMIC DNA. ACCORDINGLY, HP1 LOSS OF FUNCTION LED TO THE INCREASED DETECTION OF CGAS/STING, A CYTOPLASMIC DNA SENSOR THAT TRIGGERS INFLAMMATION. THUS, IN ADDITION TO ITS ROLE AS A TRANSCRIPTIONAL SILENCER, HP1GAMMA MAY ALSO EXERT ANTI-INFLAMMATORY PROPERTIES BY PREVENTING THE ACTIVATION OF THE ENDOGENOUS CYTOPLASMIC DNA RESPONSE IN THE GUT EPITHELIUM. 2023 13 689 37 BRD4 AS A THERAPEUTIC TARGET IN PULMONARY DISEASES. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC MODULATORS THAT REGULATE GENE TRANSCRIPTION THROUGH INTERACTING WITH ACETYLATED LYSINE RESIDUES OF HISTONE PROTEINS. BET PROTEINS HAVE MULTIPLE ROLES IN REGULATING KEY CELLULAR FUNCTIONS SUCH AS CELL PROLIFERATION, DIFFERENTIATION, INFLAMMATION, OXIDATIVE AND REDOX BALANCE, AND IMMUNE RESPONSES. AS A RESULT, BET PROTEINS HAVE BEEN FOUND TO BE ACTIVELY INVOLVED IN A BROAD RANGE OF HUMAN LUNG DISEASES INCLUDING ACUTE LUNG INFLAMMATION, ASTHMA, PULMONARY ARTERIAL HYPERTENSION, PULMONARY FIBROSIS, AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). DUE TO THE IDENTIFICATION OF SPECIFIC SMALL MOLECULAR INHIBITORS OF BET PROTEINS, TARGETING BET IN THESE LUNG DISEASES HAS BECOME AN AREA OF INCREASING INTEREST. EMERGING EVIDENCE HAS DEMONSTRATED THE BENEFICIAL EFFECTS OF BET INHIBITORS IN PRECLINICAL MODELS OF VARIOUS HUMAN LUNG DISEASES. THIS IS, IN GENERAL, LARGELY RELATED TO THE ABILITY OF BET PROTEINS TO BIND TO PROMOTERS OF GENES THAT ARE CRITICAL FOR INFLAMMATION, DIFFERENTIATION, AND BEYOND. BY MODULATING THESE CRITICAL GENES, BET PROTEINS ARE INTEGRATED INTO THE PATHOGENESIS OF DISEASE PROGRESSION. THE INTRINSIC HISTONE ACETYLTRANSFERASE ACTIVITY OF BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) IS OF PARTICULAR INTEREST, SEEMS TO ACT INDEPENDENTLY OF ITS BROMODOMAIN BINDING ACTIVITY, AND HAS IMPLICATION IN SOME CONTEXTS. IN THIS REVIEW, WE PROVIDE A BRIEF OVERVIEW OF THE RESEARCH ON BET PROTEINS WITH A FOCUS ON BRD4 IN SEVERAL MAJOR HUMAN LUNG DISEASES, THE UNDERLYING MOLECULAR MECHANISMS, AS WELL AS FINDINGS OF TARGETING BET PROTEINS USING PHARMACEUTICAL INHIBITORS IN DIFFERENT LUNG DISEASES PRECLINICALLY. 2023 14 698 39 BROMODOMAIN CONTAINING PROTEIN 4 (BRD4) REGULATES EXPRESSION OF ITS INTERACTING COACTIVATORS IN THE INNATE RESPONSE TO RESPIRATORY SYNCYTIAL VIRUS. BROMODOMAIN-CONTAINING PROTEIN 4 PLAYS A CENTRAL ROLE IN COORDINATING THE COMPLEX EPIGENETIC COMPONENT OF THE INNATE IMMUNE RESPONSE. PREVIOUS STUDIES IMPLICATED BRD4 AS A COMPONENT OF A CHROMATIN-MODIFYING COMPLEX THAT IS DYNAMICALLY RECRUITED TO A NETWORK OF PROTECTIVE CYTOKINES BY BINDING ACTIVATED TRANSCRIPTION FACTORS, POLYMERASES, AND HISTONES TO TRIGGER THEIR RAPID EXPRESSION VIA TRANSCRIPTIONAL ELONGATION. OUR PREVIOUS STUDY EXTENDED OUR UNDERSTANDING OF THE AIRWAY EPITHELIAL BRD4 INTERACTOME BY IDENTIFYING OVER 100 FUNCTIONALLY IMPORTANT COACTIVATORS AND TRANSCRIPTION FACTORS, WHOSE ASSOCIATION IS INDUCED BY RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION. RSV IS AN ETIOLOGICAL AGENT OF RECURRENT RESPIRATORY TRACT INFECTIONS ASSOCIATED WITH EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. USING A HIGHLY SELECTIVE SMALL-MOLECULE BRD4 INHIBITOR (ZL0454) DEVELOPED BY US, WE EXTEND THESE FINDINGS TO IDENTIFY THE GENE REGULATORY NETWORK DEPENDENT ON BRD4 BROMODOMAIN (BD) INTERACTIONS. HUMAN SMALL AIRWAY EPITHELIAL CELLS WERE INFECTED IN THE ABSENCE OR PRESENCE OF ZL0454, AND GENE EXPRESSION PROFILING WAS PERFORMED. A HIGHLY REPRODUCIBLE DATASET WAS OBTAINED WHICH INDICATED THAT BRD4 MEDIATES BOTH ACTIVATION AND REPRESSION OF RSV-INDUCIBLE GENE REGULATORY NETWORKS CONTROLLING CYTOKINE EXPRESSION, INTERFERON (IFN) PRODUCTION, AND EXTRACELLULAR MATRIX REMODELING. INDEX GENES OF FUNCTIONALLY SIGNIFICANT CLUSTERS WERE VALIDATED INDEPENDENTLY. WE DISCOVER THAT BRD4 REGULATES THE EXPRESSION OF ITS OWN GENE DURING THE INNATE IMMUNE RESPONSE. INTERESTINGLY, BRD4 ACTIVATES THE EXPRESSION OF NFKAPPAB/RELA, A COACTIVATOR THAT BINDS TO BRD4 IN A BD-DEPENDENT MANNER. WE EXTEND THIS FINDING TO SHOW THAT BRD4 ALSO REGULATES OTHER COMPONENTS OF ITS FUNCTIONAL INTERACTOME, INCLUDING THE MEDIATOR (MED) COACTIVATOR COMPLEX AND THE SWI/SNF-RELATED, MATRIX-ASSOCIATED, ACTIN-DEPENDENT REGULATOR OF CHROMATIN (SMARC) SUBUNITS. TO PROVIDE FURTHER INSIGHT INTO MECHANISMS FOR BRD4 IN RSV EXPRESSION, WE MAPPED 7,845 RSV-INDUCIBLE TN5 TRANSPOSASE PEAKS ONTO THE BRD4-DEPENDENT GENE BODIES. THESE WERE LOCATED IN PROMOTERS AND INTRONS OF CYTOSTRUCTURAL AND EXTRACELLULAR MATRIX (ECM) FORMATION GENES. THESE DATA INDICATE THAT BRD4 MEDIATES THE DYNAMIC RESPONSE OF AIRWAY EPITHELIAL CELLS TO RNA INFECTION BY MODULATING THE EXPRESSION OF ITS COACTIVATORS, CONTROLLING THE EXPRESSION OF HOST DEFENSE MECHANISMS AND REMODELING GENES THROUGH CHANGES IN PROMOTER ACCESSIBILITY. 2021 15 592 35 BET BROMODOMAIN PROTEINS REGULATE TRANSCRIPTIONAL REPROGRAMMING IN GENETIC DILATED CARDIOMYOPATHY. THE BROMODOMAIN AND EXTRATERMINAL (BET) FAMILY COMPRISES EPIGENETIC READER PROTEINS THAT ARE IMPORTANT REGULATORS OF INFLAMMATORY AND HYPERTROPHIC GENE EXPRESSION IN THE HEART. WE PREVIOUSLY IDENTIFIED THE ACTIVATION OF PROINFLAMMATORY GENE NETWORKS AS A KEY EARLY DRIVER OF DILATED CARDIOMYOPATHY (DCM) IN TRANSGENIC MICE EXPRESSING A MUTANT FORM OF PHOSPHOLAMBAN (PLNR9C) - A GENETIC CAUSE OF DCM IN HUMANS. WE HYPOTHESIZED THAT BETS COACTIVATE THIS INFLAMMATORY PROCESS, REPRESENTING A CRITICAL NODE IN THE PROGRESSION OF DCM. TO TEST THIS HYPOTHESIS, WE TREATED PLNR9C OR AGE-MATCHED WT MICE LONGITUDINALLY WITH THE SMALL MOLECULE BET BROMODOMAIN INHIBITOR JQ1 OR VEHICLE. BET INHIBITION ABROGATED ADVERSE CARDIAC REMODELING, REDUCED CARDIAC FIBROSIS, AND PROLONGED SURVIVAL IN PLNR9C MICE BY INHIBITING EXPRESSION OF PROINFLAMMATORY GENE NETWORKS AT ALL STAGES OF DISEASE. SPECIFICALLY, JQ1 HAD PROFOUND EFFECTS ON PROINFLAMMATORY GENE NETWORK EXPRESSION IN CARDIAC FIBROBLASTS, WHILE HAVING LITTLE EFFECT ON GENE EXPRESSION IN CARDIOMYOCYTES. CARDIAC FIBROBLAST PROLIFERATION WAS ALSO SUBSTANTIALLY REDUCED BY JQ1. MECHANISTICALLY, WE DEMONSTRATED THAT BRD4 SERVES AS A DIRECT AND ESSENTIAL REGULATOR OF NF-KAPPAB-MEDIATED PROINFLAMMATORY GENE EXPRESSION IN CARDIAC FIBROBLASTS. SUPPRESSING PROINFLAMMATORY GENE EXPRESSION VIA BET BROMODOMAIN INHIBITION COULD BE A NOVEL THERAPEUTIC STRATEGY FOR CHRONIC DCM IN HUMANS. 2020 16 595 30 BET PROTEINS REGULATE EXPRESSION OF OSR1 IN EARLY KIDNEY DEVELOPMENT. IN UTERO RENAL DEVELOPMENT IS SUBJECT TO MATERNAL METABOLIC AND ENVIRONMENTAL INFLUENCES AFFECTING LONG-TERM RENAL FUNCTION AND THE RISK OF DEVELOPING CHRONIC KIDNEY FAILURE AND CARDIOVASCULAR DISEASE. EPIGENETIC PROCESSES HAVE BEEN IMPLICATED IN THE ORCHESTRATION OF RENAL DEVELOPMENT AND PRENATAL PROGRAMMING OF NEPHRON NUMBER. HOWEVER, THE ROLE OF MANY EPIGENETIC MODIFIERS FOR KIDNEY DEVELOPMENT IS STILL UNCLEAR. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ACT AS HISTONE ACETYLATION READER MOLECULES AND PROMOTE GENE TRANSCRIPTION. BET FAMILY MEMBERS BRD2, BRD3 AND BRD4 ARE EXPRESSED IN THE NEPHROGENIC ZONE DURING KIDNEY DEVELOPMENT. HERE, THE EFFECT OF THE BET INHIBITOR JQ1 ON RENAL DEVELOPMENT IS EVALUATED. INHIBITION OF BET PROTEINS VIA JQ1 LEADS TO REDUCED GROWTH OF METANEPHRIC KIDNEY CULTURES, LOSS OF THE NEPHRON PROGENITOR CELL POPULATION, AND PREMATURE AND DISTURBED NEPHRON DIFFERENTIATION. GENE EXPRESSION OF KEY NEPHRON PROGENITOR TRANSCRIPTION FACTOR OSR1 IS DOWNREGULATED AFTER 24 H BET INHIBITION, WHILE LHX1 AND PAX8 EXPRESSION IS INCREASED. MINING OF BRD4 CHIP-SEQ AND GENE EXPRESSION DATA IDENTIFY OSR1 AS A KEY FACTOR REGULATED BY BRD4-CONTROLLED GENE ACTIVATION. INHIBITION OF BRD4 BY BET INHIBITOR JQ1 LEADS TO DOWNREGULATION OF OSR1, THEREBY CAUSING A DISTURBANCE IN THE BALANCE OF NEPHRON PROGENITOR CELL SELF-RENEWAL AND PREMATURE DIFFERENTIATION OF THE NEPHRON, WHICH ULTIMATELY LEADS TO KIDNEY HYPOPLASIA AND DISTURBED NEPHRON DEVELOPMENT. THIS RAISES QUESTIONS ABOUT THE POTENTIAL TERATOGENIC EFFECTS OF BET INHIBITORS FOR EMBRYONIC DEVELOPMENT. IN SUMMARY, OUR WORK HIGHLIGHTS THE ROLE OF BET PROTEINS FOR PRENATAL PROGRAMMING OF NEPHROGENESIS AND IDENTIFIES OSR1 AS A POTENTIAL TARGET OF BET PROTEINS. 2021 17 1105 37 COMBINED INHIBITION OF HISTONE DEACETYLASES AND BET FAMILY PROTEINS AS EPIGENETIC THERAPY FOR NERVE INJURY-INDUCED NEUROPATHIC PAIN. CURRENT TREATMENTS FOR NEUROPATHIC PAIN HAVE OFTEN MODERATE EFFICACY AND PRESENT UNWANTED EFFECTS SHOWING THE NEED TO DEVELOP EFFECTIVE THERAPIES. ACCUMULATING EVIDENCE SUGGESTS THAT HISTONE ACETYLATION PLAYS ESSENTIAL ROLES IN CHRONIC PAIN AND THE ANALGESIC ACTIVITY OF HISTONE DEACETYLASES (HDACS) INHIBITORS IS DOCUMENTED. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC READERS THAT INTERACT WITH ACETYLATED LYSINE RESIDUES ON HISTONES, BUT LITTLE IS KNOWN ABOUT THEIR IMPLICATION IN NEUROPATHIC PAIN. THUS, THE CURRENT STUDY WAS AIMED TO INVESTIGATE THE EFFECT OF THE COMBINATION OF HDAC AND BET INHIBITORS IN THE SPARED NERVE INJURY (SNI) MODEL IN MICE. INTRANASAL ADMINISTRATION OF I-BET762 (BET INHIBITOR) OR SAHA (HDAC INHIBITOR) ATTENUATED THERMAL AND MECHANICAL HYPERSENSITIVITY AND THIS ANTIALLODYNIC ACTIVITY WAS IMPROVED BY CO-ADMINISTRATION OF BOTH DRUGS. SPINAL CORD SECTIONS OF SNI MICE SHOWED AN INCREASED EXPRESSION OF HDAC1 AND BRD4 PROTEINS AND COMBINATION PRODUCED A STRONGER REDUCTION COMPARED TO EACH EPIGENETIC AGENT ALONE. SAHA AND I-BET762, ADMINISTERED ALONE OR IN COMBINATION, COUNTERACTED THE SNI-INDUCED MICROGLIA ACTIVATION BY INHIBITING THE EXPRESSION OF IBA1, CD11B, INDUCIBLE NITRIC OXIDE SYNTHASE (INOS), THE ACTIVATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION-1 (STAT1) WITH COMPARABLE EFFICACY. CONVERSELY, THE EPIGENETIC INHIBITORS SHOWED A MODEST EFFECT ON SPINAL PROINFLAMMATORY CYTOKINES CONTENT THAT WAS SIGNIFICANTLY POTENTIATED BY THEIR COMBINATION. PRESENT RESULTS INDICATE A KEY ROLE OF ACETYLATED HISTONES AND THEIR RECRUITMENT BY BET PROTEINS ON MICROGLIA-MEDIATED SPINAL NEUROINFLAMMATION. TARGETING NEUROPATHIC PAIN WITH THE COMBINATION OF HDAC AND BET INHIBITORS MAY REPRESENT A PROMISING NEW THERAPEUTIC OPTION. 2021 18 6453 29 THIOREDOXIN INTERACTING PROTEIN (TXNIP) INDUCES INFLAMMATION THROUGH CHROMATIN MODIFICATION IN RETINAL CAPILLARY ENDOTHELIAL CELLS UNDER DIABETIC CONDITIONS. CHRONIC HYPERGLYCEMIA AND ACTIVATION OF RECEPTOR FOR ADVANCED GLYCATION END PRODUCTS (RAGE) ARE KNOWN RISK FACTORS FOR MICROVASCULAR DISEASE DEVELOPMENT IN DIABETIC RETINOPATHY. THIOREDOXIN-INTERACTING PROTEIN (TXNIP), AN ENDOGENOUS INHIBITOR OF ANTIOXIDANT THIOREDOXIN (TRX), PLAYS A CAUSATIVE ROLE IN DIABETES AND ITS VASCULAR COMPLICATIONS. HEREIN WE INVESTIGATE WHETHER HG AND RAGE INDUCE INFLAMMATION IN RAT RETINAL ENDOTHELIAL CELLS (EC) UNDER DIABETIC CONDITIONS IN CULTURE THROUGH TXNIP ACTIVATION AND WHETHER EPIGENETIC MECHANISMS PLAY A ROLE IN INFLAMMATORY GENE EXPRESSION. WE SHOW THAT RAGE ACTIVATION BY ITS LIGAND S100B OR HG TREATMENT OF RETINAL EC INDUCES THE EXPRESSION OF TXNIP AND INFLAMMATORY GENES SUCH AS COX2, VEGF-A, AND ICAM1. TXNIP SILENCING BY SIRNA IMPEDES RAGE AND HG EFFECTS WHILE STABLE OVER-EXPRESSION OF A CDNA FOR HUMAN TXNIP IN EC ELEVATES INFLAMMATION. P38 MAPK-NF-KAPPAB SIGNALING PATHWAY AND HISTONE H3 LYSINE (K) NINE MODIFICATIONS ARE INVOLVED IN TXNIP-INDUCED INFLAMMATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAYS REVEAL THAT TXNIP OVER-EXPRESSION IN EC ABOLISHES H3K9 TRI-METHYLATION, A MARKER FOR GENE INACTIVATION, AND INCREASES H3K9 ACETYLATION, AN INDICATOR OF GENE INDUCTION, AT PROXIMAL COX2 PROMOTER BEARING THE NF-KAPPAB-BINDING SITE. THESE FINDINGS HAVE IMPORTANT IMPLICATIONS TOWARD UNDERSTANDING THE MOLECULAR MECHANISMS OF OCULAR INFLAMMATION AND ENDOTHELIAL DYSFUNCTION IN DIABETIC RETINOPATHY. 2009 19 2239 34 EPIGENETIC MODULATION BY APABETALONE COUNTERS CYTOKINE-DRIVEN ACUTE PHASE RESPONSE IN VITRO, IN MICE AND IN PATIENTS WITH CARDIOVASCULAR DISEASE. CHRONIC SYSTEMIC INFLAMMATION CONTRIBUTES TO CARDIOVASCULAR DISEASE (CVD) AND CORRELATES WITH THE ABUNDANCE OF ACUTE PHASE RESPONSE (APR) PROTEINS IN THE LIVER AND PLASMA. BROMODOMAIN AND EXTRATERMINAL (BET) PROTEINS ARE EPIGENETIC READERS THAT REGULATE INFLAMMATORY GENE TRANSCRIPTION. WE SHOW THAT BET INHIBITION BY THE SMALL MOLECULE APABETALONE REDUCES APR GENE AND PROTEIN EXPRESSION IN HUMAN HEPATOCYTES, MOUSE MODELS, AND PLASMA FROM CVD PATIENTS. STEADY-STATE EXPRESSION OF SERUM AMYLOID P, PLASMINOGEN ACTIVATOR INHIBITOR 1, AND CERULOPLASMIN, APR PROTEINS LINKED TO CVD RISK, IS REDUCED BY APABETALONE IN CULTURED HEPATOCYTES AND IN HUMANIZED MOUSE LIVER. IN CYTOKINE-STIMULATED HEPATOCYTES, APABETALONE REDUCES THE EXPRESSION OF C-REACTIVE PROTEIN (CRP), ALPHA-2-MACROGLOBULIN, AND SERUM AMYLOID P. THE LATTER TWO ARE ALSO REDUCED BY APABETALONE IN THE LIVER OF ENDOTOXEMIC MICE. BET KNOCKDOWN IN VITRO ALSO COUNTERS CYTOKINE-MEDIATED INDUCTION OF THE CRP GENE. MECHANISTICALLY, APABETALONE REDUCES THE CYTOKINE-DRIVEN INCREASE IN BRD4 BET OCCUPANCY AT THE CRP PROMOTER, CONFIRMING THAT TRANSCRIPTION OF CRP IS BET-DEPENDENT. IN PATIENTS WITH STABLE CORONARY DISEASE, PLASMA APR PROTEINS CRP, IL-1 RECEPTOR ANTAGONIST, AND FIBRINOGEN GAMMA DECREASE AFTER APABETALONE TREATMENT VERSUS PLACEBO, RESULTING IN A PREDICTED DOWNREGULATION OF THE APR PATHWAY AND CYTOKINE TARGETS. WE CONCLUDE THAT CRP AND COMPONENTS OF THE APR PATHWAY ARE REGULATED BY BET PROTEINS AND THAT APABETALONE COUNTERS CHRONIC CYTOKINE SIGNALING IN PATIENTS. 2020 20 1650 28 DOMAIN-SELECTIVE TARGETING OF BET PROTEINS IN CANCER AND IMMUNOLOGICAL DISEASES. CANCER AND INFLAMMATION ARE STRONGLY INTERCONNECTED PROCESSES. CHRONIC INFLAMMATORY PATHOLOGIES CAN BE AT THE HEART OF TUMOR DEVELOPMENT; SIMILARLY, TUMOR-ELICITED INFLAMMATION IS A CONSEQUENCE OF MANY CANCERS. THE MECHANISTIC INTERDEPENDENCE BETWEEN CANCER AND INFLAMMATORY PATHOLOGIES POINTS TOWARD COMMON PROTEIN EFFECTORS WHICH REPRESENT POTENTIAL SHARED TARGETS FOR PHARMACOLOGICAL INTERVENTION. EPIGENETIC MECHANISMS OFTEN DRIVE RESISTANCE TO CANCER THERAPY AND IMMUNOMODULATORY STRATEGIES. THE BROMODOMAIN AND EXTRATERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC ADAPTERS WHICH PLAY A MAJOR ROLE IN CONTROLLING CELL PROLIFERATION AND THE PRODUCTION OF INFLAMMATORY MEDIATORS. A PLETHORA OF SMALL MOLECULES AIMED AT INHIBITING BET PROTEIN FUNCTION TO TREAT CANCER AND INFLAMMATORY DISEASES HAVE POPULATED ACADEMIC AND INDUSTRY EFFORTS IN THE LAST 10 YEARS. IN THIS REVIEW, WE WILL DISCUSS RECENT PHARMACOLOGICAL APPROACHES AIMED AT TARGETING A SINGLE OR A SUBSET OF THE EIGHT BROMODOMAINS WITHIN THE BET FAMILY WHICH HAVE THE POTENTIAL TO TEASE APART CLINICAL EFFICACY AND SAFETY SIGNALS OF BET INHIBITORS. 2020