1 4582 145 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 2 598 25 BETA-ADRENERGIC SIGNALING PROMOTES TUMOR ANGIOGENESIS AND PROSTATE CANCER PROGRESSION THROUGH HDAC2-MEDIATED SUPPRESSION OF THROMBOSPONDIN-1. CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING HAVE BEEN SHOWN TO PROMOTE CANCER PROGRESSION, WHOSE UNDERLYING MECHANISMS ARE LARGELY UNCLEAR, ESPECIALLY THE INVOLVEMENT OF EPIGENETIC REGULATION. HISTONE DEACETYLASE-2 (HDAC2), AN EPIGENETIC REGULATOR, IS CRITICAL FOR STRESS-INDUCED CARDIAC HYPERTROPHY. IT IS UNKNOWN WHETHER IT IS NECESSARY FOR BETA-ADRENERGIC SIGNALING-PROMOTED CANCER PROGRESSION. USING XENOGRAFT MODELS, WE SHOWED THAT CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING PROMOTE ANGIOGENESIS AND PROSTATE CANCER PROGRESSION. HDAC2 WAS INDUCED BY BETA-ADRENERGIC SIGNALING IN VITRO AND IN MOUSE XENOGRAFTS. WE NEXT UNCOVERED THAT HDAC2 IS A DIRECT TARGET OF CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB) THAT IS ACTIVATED BY BETA-ADRENERGIC SIGNALING. NOTABLY, HDAC2 IS NECESSARY FOR BETA-ADRENERGIC SIGNALING TO INDUCE ANGIOGENESIS. WE FURTHER DEMONSTRATED THAT, UPON CREB ACTIVATION, HDAC2 REPRESSES THROMBOSPONDIN-1 (TSP1), A POTENT ANGIOGENESIS INHIBITOR, THROUGH EPIGENETIC REGULATION. TOGETHER, THESE DATA ESTABLISH A NOVEL PATHWAY THAT HDAC2 AND TSP1 ACT DOWNSTREAM OF CREB ACTIVATION IN BETA-ADRENERGIC SIGNALING TO PROMOTE CANCER PROGRESSION. 2017 3 3197 26 HDAC INHIBITORS: TARGETS FOR TUMOR THERAPY, IMMUNE MODULATION AND LUNG DISEASES. HISTONE DEACETYLASES (HDACS) ARE ENZYMES THAT PLAY A KEY ROLE IN THE EPIGENETIC REGULATION OF GENE EXPRESSION BY REMODELING CHROMATIN. INHIBITION OF HDACS IS A PROSPECTIVE THERAPEUTIC APPROACH FOR REVERSING EPIGENETIC ALTERATION IN SEVERAL DISEASES. IN PRECLINICAL RESEARCH, NUMEROUS TYPES OF HDAC INHIBITORS WERE DISCOVERED TO EXHIBIT POWERFUL AND SELECTIVE ANTICANCER PROPERTIES. HOWEVER, SUCH RESEARCH HAS REVEALED THAT THE EFFECTS OF HDAC INHIBITORS MAY BE FAR BROADER AND MORE INTRICATE THAN PREVIOUSLY THOUGHT. THIS REVIEW WILL PROVIDE INSIGHT INTO THE HDAC INHIBITORS AND THEIR MECHANISM OF ACTION WITH SPECIAL EMPHASIS ON THE SIGNIFICANCE OF HDAC INHIBITORS IN THE TREATMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND LUNG CANCER. NANOCARRIER-MEDIATED HDAC INHIBITOR DELIVERY AND NEW APPROACHES FOR TARGETING HDACS ARE ALSO DISCUSSED. 2022 4 3720 31 INHIBITION OF CLASS I HISTONE DEACETYLASES ABROGATES TUMOR GROWTH FACTOR BETA EXPRESSION AND DEVELOPMENT OF FIBROSIS DURING CHRONIC PANCREATITIS. PANCREATIC FIBROSIS IS THE HALLMARK OF CHRONIC PANCREATITIS, A HIGHLY DEBILITATING DISEASE FOR WHICH THERE IS CURRENTLY NO CURE. THE KEY EVENT AT THE BASIS OF PANCREATIC FIBROSIS IS THE DEPOSITION OF EXTRACELLULAR MATRIX PROTEINS BY ACTIVATED PANCREATIC STELLATE CELLS (PSCS). TRANSFORMING GROWTH FACTOR BETA (TGFBETA) IS A POTENT PROFIBROTIC FACTOR IN THE PANCREAS AS IT PROMOTES THE ACTIVATION OF PSC; THUS, PHARMACOLOGIC INTERVENTIONS THAT EFFECTIVELY REDUCE TGFBETA EXPRESSION HARBOR CONSIDERABLE THERAPEUTIC POTENTIAL IN THE TREATMENT OF CHRONIC PANCREATITIS. IN THIS STUDY, WE INVESTIGATED WHETHER TGFBETA EXPRESSION IS REDUCED BY PHARMACOLOGIC INHIBITION OF THE EPIGENETIC MODIFIERS HISTONE DEACETYLASES (HDACS). TO ADDRESS THIS AIM, CHRONIC PANCREATITIS WAS INDUCED IN C57BL/6 MICE WITH SERIAL INJECTIONS OF CERULEIN, AND THE SELECTIVE CLASS 1 HDAC INHIBITOR MS-275 WAS ADMINISTERED IN VIVO IN A PREVENTIVE AND THERAPEUTIC MANNER. BOTH MS-275 REGIMENS POTENTLY REDUCED DEPOSITION OF EXTRACELLULAR MATRIX AND DEVELOPMENT OF FIBROSIS IN THE PANCREAS AFTER 4 WEEKS OF CHRONIC PANCREATITIS. REDUCED PANCREATIC FIBROSIS WAS CONCOMITANT WITH LOWER EXPRESSION OF PANCREATIC TGFBETA AND CONSEQUENT REDUCED PSC ACTIVATION. IN SEARCH OF THE CELL TYPES TARGETED BY THE INHIBITOR, WE FOUND THAT MS-275 TREATMENT ABROGATED THE EXPRESSION OF TGFBETA IN ACINAR CELLS STIMULATED BY CERULEIN TREATMENT. OUR STUDY DEMONSTRATES THAT MS-275 IS AN EFFECTIVE ANTIFIBROTIC AGENT IN THE CONTEXT OF EXPERIMENTAL CHRONIC PANCREATITIS AND THUS MAY CONSTITUTE A VALID THERAPEUTIC INTERVENTION FOR THIS SEVERE DISEASE. 2018 5 3571 18 IMPACT OF LOCAL ANESTHETICS ON EPIGENETICS IN CANCER. DEFECTIVE SILENCING OF TUMOR SUPPRESSOR GENES THROUGH EPIGENETIC ALTERATIONS CONTRIBUTES TO ONCOGENESIS BY PERTURBING CELL CYCLE REGULATION, DNA REPAIR OR CELL DEATH MECHANISMS. REVERSAL OF SUCH EPIGENETIC CHANGES INCLUDING DNA HYPERMETHYLATION PROVIDES A PROMISING ANTICANCER STRATEGY. UNTIL NOW, THE NUCLEOSIDE DERIVATIVES 5-AZACYTIDINE AND DECITABINE ARE THE SOLE DNA METHYLTRANSFERASE (DNMT) INHIBITORS APPROVED BY THE FDA FOR THE TREATMENT OF SPECIFIC HEMATOLOGICAL CANCERS. NEVERTHELESS, DUE TO THEIR NUCLEOSIDE STRUCTURE, THESE INHIBITORS DIRECTLY INCORPORATE INTO DNA, WHICH LEADS TO SEVERE SIDE EFFECTS AND COMPROMISES GENOMIC STABILITY. MUCH EMPHASIS HAS BEEN PLACED ON THE DEVELOPMENT OF LESS TOXIC EPIGENETIC MODIFIERS. RECENTLY, SEVERAL PRECLINICAL STUDIES DEMONSTRATED THE POTENT EPIGENETIC EFFECTS OF LOCAL ANESTHETICS, WHICH ARE ROUTINELY USED DURING PRIMARY TUMOR RESECTION TO RELIEF SURGICAL PAIN. THESE NON-NUCLEOSIDE MOLECULES INHIBIT DNMT ACTIVITY, AFFECT THE EXPRESSION OF MICRO-RNAS AND REPRESS HISTONE ACETYLATION, THUS EXERTING CYTOTOXIC EFFECTS ON MALIGNANT CELLS. THE IN-DEPTH MECHANISTIC COMPREHENSION OF THESE EPIGENETIC EFFECTS MIGHT PROMOTE THE USE OF LOCAL ANESTHETICS AS ANTICANCER DRUGS. 2022 6 5939 40 TARGETING MECHANOTRANSDUCTION AT THE TRANSCRIPTIONAL LEVEL: YAP AND BRD4 ARE NOVEL THERAPEUTIC TARGETS FOR THE REVERSAL OF LIVER FIBROSIS. LIVER FIBROSIS IS THE RESULT OF A DEREGULATED WOUND HEALING PROCESS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX. HEPATIC STELLATE CELLS (HSCS), WHICH ARE ACTIVATED IN RESPONSE TO LIVER INJURY, ARE THE MAJOR SOURCE OF EXTRACELLULAR MATRIX AND DRIVE THE WOUND HEALING PROCESS. HOWEVER, CHRONIC LIVER DAMAGE LEADS TO PERPETUAL HSC ACTIVATION, PROGRESSIVE FORMATION OF PATHOLOGICAL SCAR TISSUE AND ULTIMATELY, CIRRHOSIS AND ORGAN FAILURE. HSC ACTIVATION IS TRIGGERED LARGELY IN RESPONSE TO MECHANOSIGNALING FROM THE MICROENVIRONMENT, WHICH INDUCES A PROFIBROTIC NUCLEAR TRANSCRIPTION PROGRAM THAT PROMOTES HSC PROLIFERATION AND EXTRACELLULAR MATRIX SECRETION THEREBY SETTING UP A POSITIVE FEEDBACK LOOP LEADING TO MATRIX STIFFENING AND SELF-SUSTAINED, PATHOLOGICAL, HSC ACTIVATION. DESPITE THE SIGNIFICANT PROGRESS IN OUR UNDERSTANDING OF LIVER FIBROSIS, THE MOLECULAR MECHANISMS THROUGH WHICH THE EXTRACELLULAR MATRIX PROMOTES HSC ACTIVATION ARE NOT WELL UNDERSTOOD AND NO EFFECTIVE THERAPIES HAVE BEEN APPROVED TO DATE THAT CAN TARGET THIS EARLY, REVERSIBLE, STAGE IN LIVER FIBROSIS. SEVERAL NEW LINES OF INVESTIGATION NOW PROVIDE IMPORTANT INSIGHT INTO THIS AREA OF STUDY AND IDENTIFY TWO NUCLEAR TARGETS WHOSE INHIBITION HAS THE POTENTIAL OF REVERSING LIVER FIBROSIS BY INTERFERING WITH HSC ACTIVATION: YES-ASSOCIATED PROTEIN (YAP), A TRANSCRIPTIONAL CO-ACTIVATOR AND EFFECTOR OF THE MECHANOSENSITIVE HIPPO PATHWAY, AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4), AN EPIGENETIC REGULATOR OF GENE EXPRESSION. YAP AND BRD4 ACTIVITY IS INDUCED IN RESPONSE TO MECHANICAL STIMULATION OF HSCS AND EACH PROTEIN INDEPENDENTLY CONTROLS WAVES OF EARLY GENE EXPRESSION NECESSARY FOR HSC ACTIVATION. SIGNIFICANTLY, INHIBITION OF EITHER PROTEIN CAN REVERT THE CHRONIC ACTIVATION OF HSCS AND IMPEDE PATHOLOGICAL PROGRESSION OF LIVER FIBROSIS IN CLINICALLY RELEVANT MODEL SYSTEMS. IN THIS REVIEW WE WILL DISCUSS THE ROLES OF THESE NUCLEAR CO-ACTIVATORS IN HSC ACTIVATION, THEIR MECHANISM OF ACTION IN THE FIBROTIC PROCESS IN THE LIVER AND OTHER ORGANS, AND THE POTENTIAL OF TARGETING THEIR ACTIVITY WITH SMALL MOLECULE DRUGS FOR FIBROSIS REVERSAL. 2016 7 1339 29 DESIGN, SYNTHESIS, BIOLOGICAL EVALUATION, AND STRUCTURAL CHARACTERIZATION OF POTENT HISTONE DEACETYLASE INHIBITORS BASED ON CYCLIC ALPHA/BETA-TETRAPEPTIDE ARCHITECTURES. HISTONE DEACETYLASES (HDACS) ARE A FAMILY OF ENZYMES FOUND IN BACTERIA, FUNGI, PLANTS, AND ANIMALS THAT PROFOUNDLY AFFECT CELLULAR FUNCTION BY CATALYZING THE REMOVAL OF ACETYL GROUPS FROM -N-ACETYLATED LYSINE RESIDUES OF VARIOUS PROTEIN SUBSTRATES INCLUDING HISTONES, TRANSCRIPTION FACTORS, ALPHA-TUBULIN, AND NUCLEAR IMPORTERS. ALTHOUGH THE PRECISE ROLES OF HDAC ISOFORMS IN CELLULAR FUNCTION ARE NOT YET COMPLETELY UNDERSTOOD, INHIBITION OF HDAC ACTIVITY HAS EMERGED AS A PROMISING APPROACH FOR REVERSING THE ABERRANT EPIGENETIC STATES ASSOCIATED WITH CANCER AND OTHER CHRONIC DISEASES. POTENT NEW ISOFORM-SELECTIVE HDAC INHIBITORS WOULD THEREFORE HELP EXPAND OUR UNDERSTANDING OF THE HDAC ENZYMES AND REPRESENT ATTRACTIVE LEAD COMPOUNDS FOR DRUG DESIGN, ESPECIALLY IF COMBINED WITH HIGH-RESOLUTION STRUCTURAL ANALYSES OF SUCH INHIBITORS TO SHED LIGHT ON THE THREE-DIMENSIONAL PHARMACOPHORIC FEATURES NECESSARY FOR THE FUTURE DESIGN OF MORE POTENT AND SELECTIVE COMPOUNDS. HERE WE PRESENT STRUCTURAL AND FUNCTIONAL ANALYSES OF A SERIES OF BETA-AMINO-ACID-CONTAINING HDAC INHIBITORS INSPIRED BY CYCLIC TETRAPEPTIDE NATURAL PRODUCTS. TO SURVEY A DIVERSE ENSEMBLE OF PHARMACOPHORIC CONFIGURATIONS, WE SYSTEMATICALLY VARIED THE POSITION OF THE BETA-AMINO ACID, AMINO ACID CHIRALITY, FUNCTIONALIZATION OF THE ZN(2+)-COORDINATING AMINO ACID SIDE CHAIN, AND ALKYLATION OF THE BACKBONE AMIDE NITROGEN ATOMS AROUND THE MACROCYCLE. IN MANY CASES, THE COMPOUNDS WERE A SINGLE CONFORMATION IN SOLUTION AND EXHIBITED POTENT ACTIVITIES AGAINST A NUMBER OF HDAC ISOFORMS AS WELL AS EFFECTIVE ANTIPROLIFERATIVE AND CYTOTOXIC ACTIVITIES AGAINST HUMAN TUMOR CELLS. HIGH-RESOLUTION NMR SOLUTION STRUCTURES WERE DETERMINED FOR A SELECTION OF THE INHIBITORS, PROVIDING A USEFUL MEANS OF CORRELATING DETAILED STRUCTURAL INFORMATION WITH POTENCY. THE STRUCTURE-BASED APPROACH DESCRIBED HERE IS EXPECTED TO FURNISH VALUABLE INSIGHTS TOWARD THE FUTURE DESIGN OF MORE SELECTIVE HDAC INHIBITORS. 2009 8 1035 32 CLASS I HISTONE DEACETYLASE INHIBITION IMPROVES PANCREATITIS OUTCOME BY LIMITING LEUKOCYTE RECRUITMENT AND ACINAR-TO-DUCTAL METAPLASIA. BACKGROUND AND PURPOSE: PANCREATITIS IS A COMMON INFLAMMATION OF THE PANCREAS WITH RISING INCIDENCE IN MANY COUNTRIES. DESPITE IMPROVEMENTS IN DIAGNOSTIC TECHNIQUES, THE DISEASE IS ASSOCIATED WITH HIGH RISK OF SEVERE MORBIDITY AND MORTALITY AND THERE IS AN URGENT NEED FOR NEW THERAPEUTIC INTERVENTIONS. IN THIS STUDY, WE EVALUATED WHETHER HISTONE DEACETYLASES (HDACS), KEY EPIGENETIC REGULATORS OF GENE TRANSCRIPTION, ARE INVOLVED IN THE DEVELOPMENT OF THE DISEASE. EXPERIMENTAL APPROACH: WE ANALYSED HDAC REGULATION DURING CERULEIN-INDUCED ACUTE, CHRONIC AND AUTOIMMUNE PANCREATITIS USING DIFFERENT TRANSGENIC MOUSE MODELS. THE FUNCTIONAL RELEVANCE OF CLASS I HDACS WAS TESTED WITH THE SELECTIVE INHIBITOR MS-275 IN VIVO UPON PANCREATITIS INDUCTION AND IN VITRO IN ACTIVATED MACROPHAGES AND PRIMARY ACINAR CELL EXPLANTS. KEY RESULTS: HDAC EXPRESSION AND ACTIVITY WERE UP-REGULATED IN A TIME-DEPENDENT MANNER FOLLOWING INDUCTION OF PANCREATITIS, WITH THE HIGHEST ABUNDANCE OBSERVED FOR CLASS I HDACS. CLASS I HDAC INHIBITION DID NOT PREVENT THE INITIAL ACINAR CELL DAMAGE. HOWEVER, IT EFFECTIVELY REDUCED THE INFILTRATION OF INFLAMMATORY CELLS, INCLUDING MACROPHAGES AND T CELLS, IN BOTH ACUTE AND CHRONIC PHASES OF THE DISEASE, AND DIRECTLY DISRUPTED MACROPHAGE ACTIVATION. IN ADDITION, MS-275 TREATMENT REDUCED DNA DAMAGE IN ACINAR CELLS AND LIMITED ACINAR DE-DIFFERENTIATION INTO ACINAR-TO-DUCTAL METAPLASIA IN A CELL-AUTONOMOUS MANNER BY IMPEDING THE EGF RECEPTOR SIGNALLING AXIS. CONCLUSIONS AND IMPLICATIONS: THESE RESULTS DEMONSTRATE THAT CLASS I HDACS ARE CRITICALLY INVOLVED IN THE DEVELOPMENT OF ACUTE AND CHRONIC FORMS OF PANCREATITIS AND SUGGEST THAT BLOCKADE OF CLASS I HDAC ISOFORMS IS A PROMISING TARGET TO IMPROVE THE OUTCOME OF THE DISEASE. 2017 9 1036 31 CLASS I HISTONE DEACETYLASES REGULATE P53/NF-KAPPAB CROSSTALK IN CANCER CELLS. THE TRANSCRIPTION FACTORS NF-KAPPAB AND P53 AS WELL AS THEIR CROSSTALK DETERMINE THE FATE OF TUMOR CELLS UPON THERAPEUTIC INTERVENTIONS. REPLICATIVE STRESS AND CYTOKINES PROMOTE SIGNALING CASCADES THAT LEAD TO THE CO-REGULATION OF P53 AND NF-KAPPAB. CONSEQUENTLY, NUCLEAR P53/NF-KAPPAB SIGNALING COMPLEXES ACTIVATE NF-KAPPAB-DEPENDENT SURVIVAL GENES. THE 18 HISTONE DEACETYLASES (HDACS) ARE EPIGENETIC MODULATORS THAT FALL INTO FOUR CLASSES (I-IV). INHIBITORS OF HISTONE DEACETYLASES (HDACI) BECOME INCREASINGLY APPRECIATED AS ANTI-CANCER AGENTS. BASED ON THEIR EFFECTS ON P53 AND NF-KAPPAB, WE ADDRESSED WHETHER CLINICALLY RELEVANT HDACI AFFECT THE NF-KAPPAB/P53 CROSSTALK. THE CHEMOTHERAPEUTICS HYDROXYUREA, ETOPOSIDE, AND FLUDARABINE HALT CELL CYCLE PROGRESSION, INDUCE DNA DAMAGE, AND LEAD TO DNA FRAGMENTATION. THESE AGENTS CO-INDUCE P53 AND NF-KAPPAB-DEPENDENT GENE EXPRESSION IN CELL LINES FROM BREAST AND COLON CANCER AND IN PRIMARY CHRONIC LYMPHATIC LEUKEMIA (CLL) CELLS. USING SPECIFIC HDACI, WE FIND THAT THE CLASS I SUBGROUP OF HDACS, BUT NOT THE CLASS IIB DEACETYLASE HDAC6, ARE REQUIRED FOR THE HYDROXYUREA-INDUCED CROSSTALK BETWEEN P53 AND NF-KAPPAB. HDACI DECREASE THE BASAL AND STRESS-INDUCED EXPRESSION OF P53 AND BLOCK NF-KAPPAB-REGULATED GENE EXPRESSION. WE FURTHER SHOW THAT CLASS I HDACI INDUCE SENESCENCE IN PANCREATIC CANCER CELLS WITH MUTANT P53. 2017 10 5937 35 TARGETING HISTONE DEACETYLASE ACTIVITY IN RHEUMATOID ARTHRITIS AND ASTHMA AS PROTOTYPES OF INFLAMMATORY DISEASE: SHOULD WE KEEP OUR HATS ON? CELLULAR ACTIVATION, PROLIFERATION AND SURVIVAL IN CHRONIC INFLAMMATORY DISEASES IS REGULATED NOT ONLY BY ENGAGEMENT OF SIGNAL TRANS-DUCTION PATHWAYS THAT MODULATE TRANSCRIPTION FACTORS REQUIRED FOR THESE PROCESSES, BUT ALSO BY EPIGENETIC REGULATION OF TRANSCRIPTION FACTOR ACCESS TO GENE PROMOTER REGIONS. HISTONE ACETYL TRANSFERASES COORDINATE THE RECRUITMENT AND ACTIVATION OF TRANSCRIPTION FACTORS WITH CONFORMATIONAL CHANGES IN HISTONES THAT ALLOW GENE PROMOTER EXPOSURE. HISTONE DEACETYLASES (HDACS) COUNTERACT HISTONE ACETYL TRANSFERASE ACTIVITY THROUGH THE TARGETING OF BOTH HISTONES AS WELL AS NONHISTONE SIGNAL TRANSDUCTION PROTEINS IMPORTANT IN INFLAMMATION. NUMEROUS STUDIES HAVE INDICATED THAT DEPRESSED HDAC ACTIVITY IN PATIENTS WITH INFLAMMATORY AIRWAY DISEASES MAY CONTRIBUTE TO LOCAL PROINFLAMMATORY CYTOKINE PRODUCTION AND DIMINISH PATIENT RESPONSES TO CORTICOSTEROID TREATMENT. RECENT OBSERVATIONS THAT HDAC ACTIVITY IS DEPRESSED IN RHEUMATOID ARTHRITIS PATIENT SYNOVIAL TISSUE HAVE PREDICTED THAT STRATEGIES RESTORING HDAC FUNCTION MAY BE THERAPEUTIC IN THIS DISEASE AS WELL. PHARMACOLOGICAL INHIBITORS OF HDAC ACTIVITY, HOWEVER, HAVE DEMONSTRATED POTENT THERAPEUTIC EFFECTS IN ANIMAL MODELS OF ARTHRITIS AND OTHER CHRONIC INFLAMMATORY DISEASES. IN THE PRESENT REVIEW WE ASSESS AND RECONCILE THESE OUTWARDLY PARADOXICAL STUDY RESULTS TO PROVIDE A WORKING MODEL FOR HOW ALTERATIONS IN HDAC ACTIVITY MAY CONTRIBUTE TO PATHOLOGY IN RHEUMATOID ARTHRITIS, AND HIGHLIGHT KEY QUESTIONS TO BE ANSWERED IN THE PRECLINICAL EVALUATION OF COMPOUNDS MODULATING THESE ENZYMES. 2008 11 1764 31 EARLY-IMMEDIATE GENE EGR1 IS ASSOCIATED WITH TGFBETA1 REGULATION OF EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 VIA THE CANONICAL SMAD3 SIGNALING IN HEPATIC STELLATE CELLS IN VITRO AND IN VIVO. UPON CHRONIC DAMAGE TO THE LIVER, MULTIPLE CYTOKINES STIMULATE HEPATIC STELLATE CELLS (HSCS), CAUSING THE ALTERATIONS OF GENE EXPRESSION PROFILES AND THUS LEADING TO HSC ACTIVATION, A KEY STEP IN LIVER FIBROGENESIS. ACTIVATED HSCS ARE THE DOMINANT CONTRIBUTORS TO LIVER FIBROSIS. BROMODOMAIN CONTAINING PROTEIN 4 (BRD4), AN IMPORTANT EPIGENETIC READER, WAS DEMONSTRATED TO CONCENTRATE ON HUNDREDS OF ENHANCERS ASSOCIATED WITH GENES INVOLVED IN MULTIPLE PROFIBROTIC PATHWAYS, THEREBY DIRECTING HSC ACTIVATION AND THE FIBROTIC RESPONSES. THE PRESENT STUDIES WERE DESIGNED TO EXAMINE THE EFFECT OF TRANSFORMING GROWTH FACTOR BETA-1 (TGFBETA1), THE MOST POTENT PRO-FIBROTIC CYTOKINE, ON BRD4 EXPRESSION IN HSCS AND, IF SO, ELUCIDATED THE UNDERLYING MECHANISMS IN VITRO AND IN VIVO. THE EXPERIMENTS EMPLOYED THE HETEROGENEOUS TGFBETA1 KNOCKOUT (TGFBETA1(+/-) ) MICE, GENE KNOCKDOWN IN VIVO, AND A MODEL OF THIOACETAMIDE (TAA)-INDUCED LIVER INJURY. THE RESULTS REVEALED THAT TGFBETA1 ENHANCED BRD4 EXPRESSION IN HSCS, WHICH WAS MEDIATED, AT LEAST, BY SMAD3 SIGNALING AND EARLY-IMMEDIATE GENE EGR1 (EARLY GROWTH RESPONSE-1). TGFBETA1-INDUCED SMAD3 SIGNALING INCREASED EGR1 EXPRESSION AND PROMOTED EGR1 BINDING TO BRD4 PROMOTER AT A SITE AROUND -111 BP, PROMOTING BRD4 EXPRESSION. EGR1 KNOCKDOWN REDUCED BRD4 EXPRESSION IN HSCS IN A MOUSE MODEL OF TAA-INDUCED LIVER INJURY AND LESSENED LIVER FIBROSIS. DOUBLE FLUORESCENCE STAINING DEMONSTRATED A STRONG INCREASE IN BRD4 EXPRESSION IN ACTIVATED HSCS IN FIBROTIC AREAS OF THE HUMAN LIVERS, PARALLELING THE UPREGULATION OF P-SMAD3 AND EGR1. THIS RESEARCH SUGGESTED NOVEL MOLECULAR EVENTS UNDERLYING THE ROLES OF THE MASTER PRO-FIBROTIC CYTOKINE TGFBETA1 IN HSC ACTIVATION AND LIVER FIBROGENESIS. 2022 12 699 35 BROMODOMAIN PROTEIN 4 IS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HEPATIC STELLATE CELL ACTIVATION. LIVER FIBROSIS IS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX IN LIVER. CHRONIC LIVER INJURY INDUCES THE ACTIVATION OF HEPATIC STELLATE CELL (HSCS), A KEY STEP IN LIVER FIBROGENESIS. THE ACTIVATED HSC IS THE PRIMARY SOURCE OF ECM AND CONTRIBUTES SIGNIFICANTLY TO LIVER FIBROSIS. TGFBETA1 IS THE MOST POTENT PRO-FIBROTIC CYTOKINE. BROMODOMAIN PROTEIN 4 (BRD4), AN EPIGENETIC READER OF HISTONE ACETYLATION MARKS, WAS CRUCIAL FOR PROFIBROTIC GENE EXPRESSION IN HSCS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLES OF BRD4 IN TGFBETA1-DEPENDENT HSC ACTIVATION AND LIVER FIBROSIS, FOCUSING ON TGFBETA1-INDUCED ALTERATIONS OF THE LEVELS OF THE FIBROTIC-RELATED IMPORTANT PROTEINS IN HSCS BY EMPLOYING THE HETEROZYGOUS TGFBETA1 KNOCKOUT MICE AND BRD4 KNOCKDOWN IN VIVO AND IN VITRO. RESULTS REVEALED THAT BRD4 PROTEIN LEVEL WAS SIGNIFICANTLY UPREGULATED BY TGFBETA1 AND BRD4 KNOCKDOWN REDUCED TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. BRD4 WAS REQUIRED FOR THE INFLUENCES OF TGFBETA1 ON PDGFBETA RECEPTOR AND ON THE PATHWAYS OF SMAD3, STAT3, AND AKT. BRD4 ALSO MEDIATED TGFBETA1-INDUCED INCREASES IN HISTONE ACETYLTRANSFERASE P300, THE PIVOTAL PRO-INFLAMMATORY NFKB P65, AND TISSUE INHIBITOR OF METALLOPROTEINASE 1 WHEREAS BRD4 REDUCED CASPASE-3 PROTEIN LEVELS IN HSCS DURING LIVER INJURY, INDEPENDENT OF TGFBETA1. FURTHER EXPERIMENTS INDICATED THE INTERACTION BETWEEN TGFBETA1-INDUCED BRD4 AND NFKB P65 IN HSCS AND IN LIVER OF TAA-INDUCED LIVER INJURY. HUMAN CIRRHOTIC LIVERS WERE DEMONSTRATED A PARALLEL INCREASE IN THE PROTEIN LEVELS OF BRD4 AND NFKB P65 IN HSCS. THIS STUDY REVEALED THAT BRD4 WAS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. 2023 13 593 41 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 14 1406 29 DIETARY HISTONE DEACETYLASE INHIBITORS: FROM CELLS TO MICE TO MAN. SULFORAPHANE (SFN) IS AN ISOTHIOCYANATE FOUND IN CRUCIFEROUS VEGETABLES, SUCH AS BROCCOLI AND BROCCOLI SPROUTS. THIS ANTICARCINOGEN WAS FIRST IDENTIFIED AS A POTENT INDUCER OF PHASE 2 DETOXIFICATION ENZYMES, BUT EVIDENCE IS MOUNTING THAT SFN ALSO ACTS THROUGH EPIGENETIC MECHANISMS. SFN HAS BEEN SHOWN TO INHIBIT HISTONE DEACETYLASE (HDAC) ACTIVITY IN HUMAN COLON AND PROSTATE CANCER LINES, WITH AN INCREASE IN GLOBAL AND LOCAL HISTONE ACETYLATION STATUS, SUCH AS ON THE PROMOTER REGIONS OF P21 AND BAX GENES. SFN ALSO INHIBITED THE GROWTH OF PROSTATE CANCER XENOGRAFTS AND SPONTANEOUS INTESTINAL POLYPS IN MOUSE MODELS, WITH EVIDENCE FOR ALTERED HISTONE ACETYLATION AND HDAC ACTIVITIES IN VIVO. IN HUMAN SUBJECTS, A SINGLE INGESTION OF 68 G BROCCOLI SPROUTS INHIBITED HDAC ACTIVITY IN CIRCULATING PERIPHERAL BLOOD MONONUCLEAR CELLS 3-6 H AFTER CONSUMPTION, WITH CONCOMITANT INDUCTION OF HISTONE H3 AND H4 ACETYLATION. THESE FINDINGS PROVIDE EVIDENCE THAT ONE MECHANISM OF CANCER CHEMOPREVENTION BY SFN IS VIA EPIGENETIC CHANGES ASSOCIATED WITH INHIBITION OF HDAC ACTIVITY. OTHER DIETARY AGENTS SUCH AS BUTYRATE, BIOTIN, LIPOIC ACID, GARLIC ORGANOSULFUR COMPOUNDS, AND METABOLITES OF VITAMIN E HAVE STRUCTURAL FEATURES COMPATIBLE WITH HDAC INHIBITION. THE ABILITY OF DIETARY COMPOUNDS TO DE-REPRESS EPIGENETICALLY SILENCED GENES IN CANCER CELLS, AND TO ACTIVATE THESE GENES IN NORMAL CELLS, HAS IMPORTANT IMPLICATIONS FOR CANCER PREVENTION AND THERAPY. IN A BROADER CONTEXT, THERE IS GROWING INTEREST IN DIETARY HDAC INHIBITORS AND THEIR IMPACT ON EPIGENETIC MECHANISMS AFFECTING OTHER CHRONIC CONDITIONS, SUCH AS CARDIOVASCULAR DISEASE, NEURODEGENERATION AND AGING. 2007 15 6687 26 VALIDATION OF THE EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) AS A THERAPEUTIC TARGET FOR TREATMENT OF AIRWAY REMODELING. STRUCTURAL REMODELING IS CENTRAL TO THE INITIATION AND PROGRESSION OF MANY CHRONIC LUNG DISEASES, REPRESENTING AN IMPORTANT UNMET NEED. WE EXAMINE THE EVIDENCE SUPPORTING BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) AS A VALIDATED BIOLOGICAL TARGET FOR TREATMENT OF AIRWAY REMODELING. IN EPITHELIAL CELLS AND FIBROBLASTS, BRD4 SERVES AS A SCAFFOLD FOR CHROMATIN REMODELING COMPLEXES IN ACTIVE SUPER-ENHANCERS. IN RESPONSE TO INFLAMMATORY STIMULI, BRD4 IS REPOSITIONED TO INNATE AND MESENCHYMAL GENES ACTIVATING THEIR PRODUCTION. PROOF-OF-CONCEPT STUDIES SHOW PROMISING BENEFIT OF SELECTIVE BRD4 INHIBITORS IN DISRUPTING EPITHELIAL MESENCHYMAL TRANSITION AND MYOFIBROBLAST TRANSITION IN DIVERSE MODELS OF LUNG INJURY. RECENT IDENTIFICATION OF BIOMARKERS OF BRD4 PROVIDES A BASIS FOR FURTHER DRUG DEVELOPMENT FOR APPLICATION IN VIRAL-INDUCED AIRWAY INFLAMMATION, COPD AND INTERSTITIAL LUNG DISEASES. 2020 16 2950 27 GENETIC AND EPIGENETIC DAMAGE INDUCED BY REACTIVE NITROGEN SPECIES: IMPLICATIONS IN CARCINOGENESIS. CHRONIC INFECTION AND INFLAMMATION ARE RECOGNIZED RISK FACTORS FOR HUMAN CANCER AT VARIOUS SITES. INFECTION AND INFLAMMATION CAN ACTIVATE AND INDUCE A VARIETY OF OXIDANT-GENERATING ENZYMES, INCLUDING NADPH OXIDASE AND INDUCIBLE NITRIC OXIDE SYNTHASE. REACTIVE OXYGEN AND NITROGEN SPECIES PRODUCED BY SUCH ENZYMES REACT WITH EACH OTHER TO GENERATE NEW AND MORE POTENT REACTIVE SPECIES. THESE OXIDANTS NOT ONLY CAN DAMAGE DNA AND INDUCE MUTATIONS, BUT ALSO CAN ACTIVATE ONCOGENE PRODUCTS AND/OR INACTIVATE TUMOR-SUPPRESSOR PROTEINS, THUS CONTRIBUTING TO MOST PROCESSES OF CARCINOGENESIS. APPROPRIATE TREATMENT OF INFLAMMATION SHOULD BE FURTHER EXPLORED FOR CHEMOPREVENTION OF HUMAN CANCERS, ESPECIALLY THOSE ASSOCIATED WITH CHRONIC INFLAMMATION. 2003 17 4044 28 MACROPHAGES IN OXIDATIVE STRESS AND MODELS TO EVALUATE THE ANTIOXIDANT FUNCTION OF DIETARY NATURAL COMPOUNDS. ANTIOXIDANT TESTING OF NATURAL PRODUCTS HAS ATTRACTED INCREASING INTEREST IN RECENT YEARS, MAINLY DUE TO THE FACT THAT AN ANTIOXIDANT-RICH DIET MIGHT PROVIDE HEALTH BENEFITS. ACTIVATED MACROPHAGES ARE A MAJOR SOURCE OF REACTIVE OXYGEN SPECIES, REACTIVE NITROGEN SPECIES, AND PEROXYNITRITE GENERATED THROUGH THE SO-CALLED RESPIRATORY BURST. CONSTITUTIVELY RELEASED PROINFLAMMATORY CYTOKINE, ESPECIALLY TUMOR NECROSIS FACTOR-ALPHA, TRIGGERS NUCLEAR FACTOR-KAPPAB, AND ACTIVATOR PROTEIN-1 TRANSLOCATION LEADING TO THE OVER PRODUCTION OF REACTIVE OXYGEN SPECIES AND REACTIVE NITROGEN SPECIES IN MACROPHAGES. ACTIVATION OF TRANSCRIPTION FACTORS IN THE LONG-LIVED TISSUE-RESIDENT MACROPHAGES AND/OR MONOCYTE-DERIVED MACROPHAGES, TRIGGER EPIGENETIC MODIFICATIONS LEADING TO THE PATHOGENESIS OF CHRONIC DISEASES. NUTRACEUTICALS INCLUDING LIPID RAFT STRUCTURE DISRUPTION AGENT, CHOLESTEROL DEPLETION AGENT, FARNESYLTRANSFERASE INHIBITOR, NUCLEAR FACTOR-KAPPAB BLOCKER (ALPHA,BETA-UNSATURATED CARBONYL COMPOUNDS), GLUCOCORTICOID RECEPTOR AGONIST, AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AGONIST HAVE LONG BEEN USED TO INACTIVE MACROPHAGE. THE INHIBITION EFFECTS ON THE FORMATION OF NITRIC OXIDE, SUPEROXIDE, AND NITRITE PEROXIDE MAY BE RESPONSIBLE FOR THE ANTI-INFLAMMATORY FUNCTIONALITIES. ACTIVATED MACROPHAGE MODELS COULD BE USED TO IDENTIFY THE ACTIVE COMPONENTS FOR FUNCTIONAL DIETS DEVELOPMENT THROUGH A MULTIPLE TARGETS STRATEGY. 2017 18 5489 27 REVERSING POST-INFECTIOUS EPIGENETIC-MEDIATED IMMUNE SUPPRESSION. THE IMMUNE RESPONSE MUST BALANCE THE PRO-INFLAMMATORY, CELL-MEDIATED CYTOTOXICITY WITH THE ANTI-INFLAMMATORY AND WOUND REPAIR RESPONSE. EPIGENETIC MECHANISMS MEDIATE THIS BALANCE AND LIMIT HOST IMMUNITY FROM INDUCING EXUBERANT COLLATERAL DAMAGE TO HOST TISSUE AFTER SEVERE AND CHRONIC INFECTIONS. HOWEVER, FOLLOWING TREATMENT FOR THESE INFECTIONS, INCLUDING SEPSIS, PNEUMONIA, HEPATITIS B, HEPATITIS C, HIV, TUBERCULOSIS (TB) OR SCHISTOSOMIASIS, DETRIMENTAL EPIGENETIC SCARS PERSIST, AND RESULT IN LONG-LASTING IMMUNE SUPPRESSION. THIS IS HYPOTHESIZED TO BE ONE OF THE CONTRIBUTING MECHANISMS EXPLAINING WHY SURVIVORS OF INFECTION HAVE INCREASED ALL-CAUSE MORTALITY AND INCREASED RATES OF UNRELATED SECONDARY INFECTIONS. THE MECHANISMS THAT INDUCE EPIGENETIC-MEDIATED IMMUNE SUPPRESSION HAVE BEEN DEMONSTRATED IN-VITRO AND IN ANIMAL MODELS. MODULATION OF THE AMP-ACTIVATED PROTEIN KINASE (AMPK)-MAMMALIAN TARGET OF RAPAMYCIN (MTOR), NUCLEAR FACTOR OF ACTIVATED T CELLS (NFAT) OR NUCLEAR RECEPTOR (NR4A) PATHWAYS IS ABLE TO BLOCK OR REVERSE THE DEVELOPMENT OF DETRIMENTAL EPIGENETIC SCARS. SIMILARLY, DRUGS THAT DIRECTLY MODIFY EPIGENETIC ENZYMES, SUCH AS THOSE THAT INHIBIT HISTONE DEACETYLASES (HDAC) INHIBITORS, DNA HYPOMETHYLATING AGENTS OR MODIFIERS OF THE NUCLEOSOME REMODELING AND DNA METHYLATION (NURD) COMPLEX OR POLYCOMB REPRESSIVE COMPLEX (PRC) HAVE DEMONSTRATED CAPACITY TO RESTORE HOST IMMUNITY IN THE SETTING OF CANCER-, LCMV- OR MURINE SEPSIS-INDUCED EPIGENETIC-MEDIATED IMMUNE SUPPRESSION. A THIRD CLINICALLY FEASIBLE STRATEGY FOR REVERSING DETRIMENTAL EPIGENETIC SCARS INCLUDES BIOENGINEERING APPROACHES TO EITHER DIRECTLY REVERSE THE DETRIMENTAL EPIGENETIC MARKS OR TO MODIFY THE EPIGENETIC ENZYMES OR TRANSCRIPTION FACTORS THAT INDUCE DETRIMENTAL EPIGENETIC SCARS. EACH OF THESE APPROACHES, ALONE OR IN COMBINATION, HAVE ABLATED OR REVERSED DETRIMENTAL EPIGENETIC MARKS IN IN-VITRO OR IN ANIMAL MODELS; TRANSLATIONAL STUDIES ARE NOW REQUIRED TO EVALUATE CLINICAL APPLICABILITY. 2021 19 5561 32 ROLE OF HISTONE DEACETYLASES IN MONOCYTE FUNCTION IN HEALTH AND CHRONIC INFLAMMATORY DISEASES. HISTONE DEACETYLASES (HDACS) ARE A FAMILY OF 18 MEMBERS THAT PARTICIPATE IN THE EPIGENETIC REGULATION OF GENE EXPRESSION. IN ADDITION TO HISTONES, SOME HDACS ALSO DEACETYLATE TRANSCRIPTION FACTORS AND SPECIFIC CYTOPLASMIC PROTEINS.MONOCYTES, AS PART OF THE INNATE IMMUNE SYSTEM, MAINTAIN TISSUE HOMEOSTASIS AND HELP FIGHT INFECTIONS AND CANCER. IN THESE CELLS, HDACS ARE INVOLVED IN MULTIPLE PROCESSES INCLUDING PROLIFERATION, MIGRATION, DIFFERENTIATION, INFLAMMATORY RESPONSE, INFECTIONS, AND TUMORIGENESIS. HERE, A SYSTEMATIC DESCRIPTION OF THE ROLE THAT MOST HDACS PLAY IN THESE FUNCTIONS IS REVIEWED. SPECIFICALLY, SOME HDACS INDUCE A PRO-INFLAMMATORY RESPONSE AND PLAY MAJOR ROLES IN HOST DEFENSE. CONVERSELY, OTHER HDACS REPROGRAM MONOCYTES AND MACROPHAGES TOWARDS AN IMMUNOSUPPRESSIVE PHENOTYPE. THE RIGHT BALANCE BETWEEN BOTH TYPES HELPS MONOCYTES TO RESPOND CORRECTLY TO THE DIFFERENT PHYSIOLOGICAL/PATHOLOGICAL STIMULI. HOWEVER, ABERRANT EXPRESSIONS OR ACTIVITIES OF SPECIFIC HDACS ARE ASSOCIATED WITH AUTOIMMUNE DISEASES ALONG WITH OTHER CHRONIC INFLAMMATORY DISEASES, INFECTIONS, OR CANCER.THIS PAPER CRITICALLY REVIEWS THE INTERESTING AND EXTENSIVE KNOWLEDGE REGARDING THE ROLE OF SOME HDACS IN THESE PATHOLOGIES. IT ALSO SHOWS THAT AS YET, VERY LITTLE PROGRESS HAS BEEN MADE TOWARD THE GOAL OF FINDING EFFECTIVE HDAC-TARGETED THERAPIES. HOWEVER, GIVEN THEIR OBVIOUS POTENTIAL, WE CONCLUDE THAT IT IS WORTH THE EFFORT TO DEVELOP MONOCYTE-SPECIFIC DRUGS THAT SELECTIVELY TARGET HDAC SUBTYPES WITH THE AIM OF FINDING EFFECTIVE TREATMENTS FOR DISEASES IN WHICH OUR INNATE IMMUNE SYSTEM IS INVOLVED. 2021 20 6757 36 WNT SIGNALING IN LIVER FIBROSIS: PROGRESS, CHALLENGES AND POTENTIAL DIRECTIONS. LIVER FIBROSIS IS A COMMON WOUND-HEALING RESPONSE TO CHRONIC LIVER INJURIES, INCLUDING ALCOHOLIC OR DRUG TOXICITY, PERSISTENT VIRAL INFECTION, AND GENETIC FACTORS. MYOFIBROBLASTIC TRANSDIFFERENTIATION (MTD) IS THE PIVOTAL EVENT DURING LIVER FIBROGENESIS, AND RESEARCH IN THE PAST FEW YEARS HAS IDENTIFIED KEY MEDIATORS AND MOLECULAR MECHANISMS RESPONSIBLE FOR MTD OF HEPATIC STELLATE CELLS (HSCS). HSCS ARE UNDIFFERENTIATED CELLS WHICH PLAY AN IMPORTANT ROLE IN LIVER REGENERATION. RECENT EVIDENCE DEMONSTRATES THAT HSCS DERIVE FROM MESODERM AND AT LEAST IN PART VIA SEPTUM TRANSVERSUM AND MESOTHELIUM, AND HSCS EXPRESS MARKERS FOR DIFFERENT CELL TYPES WHICH DERIVE FROM MULTIPOTENT MESENCHYMAL PROGENITORS. THERE IS A REGULATORY COMMONALITY BETWEEN DIFFERENTIATION OF ADIPOCYTES AND THAT OF HSC, AND THE SHIFT FROM ADIPOGENIC TO MYOGENIC OR NEURONAL PHENOTYPE CHARACTERIZES HSC MTD. CENTRAL OF THIS SHIFT IS A LOSS OF EXPRESSION OF THE MASTER ADIPOGENIC REGULATOR PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR GAMMA (PPARGAMMA). RESTORED EXPRESSION OF PPARGAMMA AND/OR OTHER ADIPOGENIC TRANSCRIPTION GENES CAN REVERSE MYOFIBROBLASTIC HSCS TO DIFFERENTIATED CELLS. VERTEBRATE WNT AND DROSOPHILA WINGLESS ARE HOMOLOGOUS GENES, AND THEIR TRANSLATED PROTEINS HAVE BEEN SHOWN TO PARTICIPATE IN THE REGULATION OF CELL PROLIFERATION, CELL POLARITY, CELL DIFFERENTIATION, AND OTHER BIOLOGICAL ROLES. MORE RECENTLY, WNT SIGNALING IS IMPLICATED IN HUMAN FIBROSING DISEASES, SUCH AS PULMONARY FIBROSIS, RENAL FIBROSIS, AND LIVER FIBROSIS. BLOCKING THE CANONICAL WNT SIGNAL PATHWAY WITH THE CO-RECEPTOR ANTAGONIST DICKKOPF-1 (DKK1) ABROGATES THESE EPIGENETIC REPRESSIONS AND RESTORES THE GENE PPARGAMMA EXPRESSION AND HSC DIFFERENTIATION. THE IDENTIFIED MORPHOGEN MEDIATED EPIGENETIC REGULATION OF PPARGAMMA AND HSC DIFFERENTIATION ALSO SERVES AS NOVEL THERAPEUTIC TARGETS FOR LIVER FIBROSIS AND LIVER REGENERATION. IN CONCLUSION, THE WNT SIGNALING PROMOTES LIVER FIBROSIS BY ENHANCING HSC ACTIVATION AND SURVIVAL, AND WE HEREIN DISCUSS WHAT WE CURRENTLY KNOW AND WHAT WE EXPECT WILL COME IN THIS FIELD IN THE NEXT FUTURE. 2013