1 729 93 CANCER ANGIOGENESIS INDUCED BY KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS IS MEDIATED BY EZH2. EZH2 IS A COMPONENT OF THE EPIGENETIC REGULATOR PRC2 THAT SUPPRESSES GENE EXPRESSION. ELEVATED EXPRESSION OF EZH2 IS COMMON IN HUMAN CANCERS AND IS ASSOCIATED WITH TUMOR PROGRESSION AND POOR PROGNOSIS. IN THIS STUDY, WE SHOW THAT EZH2 ELEVATION IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS OF KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS (KSHV), AN ONCOGENIC VIRUS THAT PROMOTES THE DEVELOPMENT OF KAPOSI SARCOMA AND OTHER MALIGNANCIES THAT OCCUR IN PATIENTS WITH CHRONIC HIV INFECTIONS. KSHV INDUCTION OF EZH2 EXPRESSION WAS ESSENTIAL FOR KSHV-INDUCED ANGIOGENESIS. HIGH EXPRESSION OF EZH2 WAS OBSERVED IN KAPOSI SARCOMA TUMORS. IN CELL CULTURE, LATENT KSHV INFECTION UPREGULATED THE EXPRESSION OF EZH2 IN HUMAN ENDOTHELIAL CELLS THROUGH THE EXPRESSION OF VFLIP AND LANA, TWO KSHV-LATENT GENES THAT ACTIVATE THE NF-KAPPAB PATHWAY. KSHV-MEDIATED UPREGULATION OF EZH2 WAS REQUIRED FOR THE INDUCTION OF EPHRIN-B2, AN ESSENTIAL PROANGIOGENIC FACTOR THAT DRIVES ENDOTHELIAL CELL TUBULE FORMATION. TAKEN TOGETHER, OUR FINDINGS INDICATE THAT KSHV REGULATES THE HOST EPIGENETIC MODIFIER EZH2 TO PROMOTE ANGIOGENESIS. 2012 2 3874 36 KAPOSI'S SARCOMA-ASSOCIATED HERPESVIRUS IMMEDIATE EARLY PROTEINS TRIGGER FOXQ1 EXPRESSION IN ORAL EPITHELIAL CELLS, ENGAGING IN A NOVEL LYTIC CYCLE-SUSTAINING POSITIVE FEEDBACK LOOP. KAPOSI'S SARCOMA-ASSOCIATED HERPESVIRUS (KSHV) IS AN ONCOGENIC GAMMAHERPESVIRUS THAT CAN REPLICATE IN ORAL EPITHELIAL CELLS TO PROMOTE VIRAL TRANSMISSION VIA SALIVA. TO IDENTIFY NOVEL REGULATORS OF KSHV ORAL INFECTION, WE PERFORMED A TRANSCRIPTOME ANALYSIS OF KSHV-INFECTED PRIMARY HUMAN GINGIVAL EPITHELIAL (HGEP) CELLS, WHICH IDENTIFIED THE GENE CODING FOR THE HOST TRANSCRIPTION FACTOR FOXQ1 AS THE TOP INDUCED HOST GENE. FOXQ1 IS NEARLY UNDETECTABLE IN UNINFECTED HGEP AND TELOMERASE-IMMORTALIZED GINGIVAL KERATINOCYTES (TIGK) CELLS BUT IS HIGHLY EXPRESSED WITHIN HOURS OF KSHV INFECTION. WE FOUND THAT WHILE THE FOXQ1 PROMOTER LACKS ACTIVATING HISTONE ACETYLATION MARKS IN UNINFECTED ORAL EPITHELIAL CELLS, THESE MARKS ACCUMULATE IN THE FOXQ1 PROMOTER IN INFECTED CELLS, REVEALING A RAPID EPIGENETIC REPROGRAMMING EVENT. TO EVALUATE FOXQ1 FUNCTION, WE DEPLETED FOXQ1 IN KSHV-INFECTED TIGK CELLS, WHICH RESULTED IN REDUCED ACCUMULATION OF KSHV LYTIC PROTEINS AND VIRAL DNA OVER THE COURSE OF 4 DAYS OF INFECTION, UNCOVERING A NOVEL LYTIC CYCLE-SUSTAINING ROLE OF FOXQ1. A SCREEN OF KSHV LYTIC PROTEINS DEMONSTRATED THAT THE IMMEDIATE EARLY PROTEINS ORF45 AND REPLICATION AND TRANSCRIPTION ACTIVATOR (RTA) WERE BOTH SUFFICIENT FOR FOXQ1 INDUCTION IN ORAL EPITHELIAL CELLS, INDICATING ACTIVE INVOLVEMENT OF INCOMING AND RAPIDLY EXPRESSED FACTORS IN ALTERING HOST GENE EXPRESSION. ORF45 IS KNOWN TO SUSTAIN EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK) P90 RIBOSOMAL S6 KINASE (RSK) PATHWAY ACTIVITY TO PROMOTE LYTIC INFECTION. WE FOUND THAT AN ORF45 MUTANT LACKING RSK ACTIVATION FUNCTION FAILED TO INDUCE FOXQ1 IN TIGK CELLS, REVEALING THAT ORF45 USES A SHARED MECHANISM TO RAPIDLY INDUCE BOTH HOST AND VIRAL GENES TO SUSTAIN LYTIC INFECTION IN ORAL EPITHELIAL CELLS. IMPORTANCE THE ORAL CAVITY IS A PRIMARY SITE OF INITIAL CONTACT AND ENTRY FOR MANY VIRUSES. VIRAL REPLICATION IN THE ORAL EPITHELIUM PROMOTES VIRAL SHEDDING IN SALIVA, ALLOWING INTERPERSONAL TRANSMISSION, AS WELL AS SPREAD TO OTHER CELL TYPES, WHERE CHRONIC INFECTION CAN BE ESTABLISHED. UNDERSTANDING THE REGULATION OF KSHV INFECTION IN THE ORAL EPITHELIUM WOULD ALLOW FOR THE DESIGN OF UNIVERSAL STRATEGIES TO TARGET THE FIRST STAGE OF VIRAL INFECTION, THEREBY HALTING SYSTEMIC VIRAL PATHOGENESIS. OVERALL, WE UNCOVER A NOVEL POSITIVE FEEDBACK LOOP IN WHICH IMMEDIATE EARLY KSHV FACTORS DRIVE RAPID HOST REPROGRAMMING OF ORAL EPITHELIAL CELLS TO SUSTAIN THE LYTIC CYCLE IN THE ORAL CAVITY. 2023 3 3891 38 KSHV VIL-6 ENHANCES INFLAMMATORY RESPONSES BY EPIGENETIC REPROGRAMMING. KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS (KSHV) INFLAMMATORY CYTOKINE SYNDROME (KICS) IS A NEWLY DESCRIBED CHRONIC INFLAMMATORY DISEASE CONDITION CAUSED BY KSHV INFECTION AND IS CHARACTERIZED BY HIGH KSHV VIRAL LOAD AND SUSTAINED ELEVATIONS OF SERUM KSHV-ENCODED IL-6 (VIL-6) AND HUMAN IL-6 (HIL-6). KICS HAS SIGNIFICANT IMMORTALITY AND POSSESSES GREATER RISKS OF HAVING OTHER COMPLICATIONS, WHICH INCLUDE MALIGNANCIES. ALTHOUGH PROLONGED INFLAMMATORY VIL-6 EXPOSURE BY PERSISTENT KSHV INFECTION IS EXPECTED TO HAVE KEY ROLES IN SUBSEQUENT DISEASE DEVELOPMENT, THE BIOLOGICAL EFFECTS OF PROLONGED VIL-6 EXPOSURE REMAIN ELUSIVE. USING THIOL-LINKED ALKYLATION FOR THE METABOLIC SEQUENCING AND CLEAVAGE UNDER TARGET & RELEASE USING NUCLEASE ANALYSIS, WE STUDIED THE EFFECT OF PROLONGED VIL-6 EXPOSURE IN CHROMATIN LANDSCAPE AND RESULTING CYTOKINE PRODUCTION. THE STUDIES SHOWED THAT PROLONGED VIL-6 EXPOSURE INCREASED BROMODOMAIN CONTAINING 4 (BRD4) AND HISTONE H3 LYSINE 27 ACETYLATION CO-OCCUPANCIES ON CHROMATIN, AND THE RECRUITMENT SITES WERE FREQUENTLY CO-LOCALIZED WITH POISED RNAPII WITH ASSOCIATED ENZYMES. INCREASED BRD4 RECRUITMENT ON PROMOTERS WAS ASSOCIATED WITH INCREASED AND PROLONGED NF-KB P65 BINDING AFTER THE LIPOPOLYSACCHARIDE STIMULATION. THE P65 BINDING RESULTED IN QUICKER AND SUSTAINED TRANSCRIPTION BURSTS FROM THE PROMOTERS; THIS MECHANISM INCREASED TOTAL AMOUNTS OF HIL-6 AND IL-10 IN TISSUE CULTURE. PRETREATMENT WITH THE BRD4 INHIBITOR, OTX015, ELIMINATED THE ENHANCED INFLAMMATORY CYTOKINE PRODUCTION. THESE FINDINGS SUGGEST THAT PERSISTENT VIL-6 EXPOSURE MAY ESTABLISH A CHROMATIN LANDSCAPE FAVORABLE FOR THE REACTIVATION OF INFLAMMATORY RESPONSES IN MONOCYTES. THIS EPIGENETIC MEMORY MAY EXPLAIN THE GREATER RISK OF CHRONIC INFLAMMATORY DISEASE DEVELOPMENT IN KSHV-INFECTED INDIVIDUALS. AUTHOR SUMMARY: COMBINED AND CONTINUOUS CYTOKINE STIMULATION TRIGGERS TRANSCRIPTION REPROGRAMMING AND IS OFTEN USED FOR SPECIFIC TISSUE DEVELOPMENT. CONTINUOUS VIL-6 EXPOSURE OCCURS IN KSHV-INFECTED PATIENTS AND LEADS TO INFLAMMATORY CYTOKINE STORM WITH HIGH MORTALITY. HOWEVER, POSSIBLE EPIGENETIC REPROGRAMMING BY THE VIL-6 AND ITS ASSOCIATION WITH PATHOGENESIS REMAIN UNCLEAR. HERE WE DEMONSTRATE THE ESTABLISHMENT OF A NEW CHROMATIN LANDSCAPE MEDIATED BY BRD4 THROUGH PROLONGED VIL-6 EXPOSURE WHICH CONTRIBUTES TO MORE ROBUST AND RAPID TRANSCRIPTION AND INCREASED CYTOKINES PRODUCTION. INHIBITION OF BRD4 SUPPRESSED THIS INFLAMMATORY RESPONSE. OUR RESULTS INDICATE THAT TARGETING THE EPIGENETIC EFFECT OF VIRAL CYTOKINES MAY LEAD TO NOVEL THERAPIES FOR KSHV-INDUCED INFLAMMATORY CYTOKINE STORMS. 2023 4 698 41 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 5 699 24 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 6 3246 24 HEPATITIS B VIRUS (HBV) INDUCES THE EXPRESSION OF INTERLEUKIN-8 THAT IN TURN REDUCES HBV SENSITIVITY TO INTERFERON-ALPHA. HIGH LEVELS OF SERUM INTERLEUKIN-8 (IL-8) HAVE BEEN DETECTED IN CHRONIC HEPATITIS B (CHB) PATIENTS DURING EPISODES OF HEPATITIS FLARES. WE INVESTIGATED WHETHER HEPATITIS B VIRUS (HBV) MAY DIRECTLY INDUCE IL-8 PRODUCTION AND WHETHER IL-8 MAY ANTAGONIZE INTERFERON-ALPHA (IFN-ALPHA) ANTIVIRAL ACTIVITY AGAINST HBV. WE SHOWED THAT CHB PATIENTS HAD SIGNIFICANTLY HIGHER IL-8 LEVELS BOTH IN SERUM AND IN LIVER TISSUE THAN CONTROLS. IN HBV-REPLICATING HEPG2 CELLS, IL-8 TRANSCRIPTION WAS SIGNIFICANTLY ACTIVATED. AP-1, C/EBP AND NF-KB TRANSCRIPTION FACTORS WERE CONCURRENTLY NECESSARY FOR MAXIMUM IL-8 INDUCTION. MOREOVER, HBX VIRAL PROTEIN WAS RECRUITED ONTO THE IL-8 PROMOTER AND THIS WAS PARALLELED BY IL8-BOUND HISTONE HYPERACETYLATION AND BY ACTIVE RECRUITMENT OF TRANSCRIPTIONAL COACTIVATORS. INHIBITION OF IL-8 INCREASES THE ANTIVIRAL ACTIVITY OF IFN-ALPHA AGAINST HBV. OUR RESULTS INDICATE THAT HBV ACTIVATES IL-8 GENE EXPRESSION BY TARGETING THE EPIGENETIC REGULATION OF THE IL-8 PROMOTER AND THAT IL-8 MAY CONTRIBUTE TO REDUCE HBV SENSITIVITY TO IFN-ALPHA. 2013 7 4546 31 MUTANT P53 REGULATES ENHANCER-ASSOCIATED H3K4 MONOMETHYLATION THROUGH INTERACTIONS WITH THE METHYLTRANSFERASE MLL4. MONOMETHYLATION OF HISTONE H3 LYSINE 4 (H3K4ME1) IS ENRICHED AT ENHANCERS THAT ARE PRIMED FOR ACTIVATION AND THE LEVELS OF THIS HISTONE MARK ARE FREQUENTLY ALTERED IN VARIOUS HUMAN CANCERS. YET, HOW ALTERATIONS IN H3K4ME1 ARE ESTABLISHED AND THE CONSEQUENCES OF THESE EPIGENETIC CHANGES IN TUMORIGENESIS ARE NOT WELL UNDERSTOOD. USING CHIP-SEQ IN HUMAN COLON CANCER CELLS, WE DEMONSTRATE THAT MUTANT P53 DEPLETION RESULTS IN DECREASED H3K4ME1 LEVELS AT ACTIVE ENHANCERS THAT REVEAL A STRIKING COLOCALIZATION OF MUTANT P53 AND THE H3K4 MONOMETHYLTRANSFERASE MLL4 FOLLOWING CHRONIC TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) SIGNALING. WE FURTHER REVEAL THAT MUTANT P53 FORMS PHYSIOLOGICAL ASSOCIATIONS AND DIRECT INTERACTIONS WITH MLL4 AND PROMOTES THE ENHANCER BINDING OF MLL4, WHICH IS REQUIRED FOR TNFALPHA-INDUCIBLE H3K4ME1 AND HISTONE H3 LYSINE 27 ACETYLATION (H3K27AC) LEVELS, ENHANCER-DERIVED TRANSCRIPT (ERNA) SYNTHESIS, AND MUTANT P53-DEPENDENT TARGET GENE ACTIVATION. COMPLEMENTARY IN VITRO STUDIES WITH RECOMBINANT CHROMATIN AND PURIFIED PROTEINS DEMONSTRATE THAT BINDING OF THE MLL3/4 COMPLEX AND H3K4ME1 DEPOSITION IS ENHANCED BY MUTANT P53 AND P300-MEDIATED ACETYLATION, WHICH IN TURN REFLECTS A MLL3/4-DEPENDENT ENHANCEMENT OF MUTANT P53 AND P300-DEPENDENT TRANSCRIPTIONAL ACTIVATION. COLLECTIVELY, OUR FINDINGS ESTABLISH A MECHANISM IN WHICH MUTANT P53 COOPERATES WITH MLL4 TO REGULATE ABERRANT ENHANCER ACTIVITY AND TUMOR-PROMOTING GENE EXPRESSION IN RESPONSE TO CHRONIC IMMUNE SIGNALING. 2018 8 5795 33 STAT3 INDUCTION OF MIR-146B FORMS A FEEDBACK LOOP TO INHIBIT THE NF-KAPPAB TO IL-6 SIGNALING AXIS AND STAT3-DRIVEN CANCER PHENOTYPES. INTERLEUKIN-6 (IL-6)-MEDIATED ACTIVATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) IS A MECHANISM BY WHICH CHRONIC INFLAMMATION CAN CONTRIBUTE TO CANCER AND IS A COMMON ONCOGENIC EVENT. WE DISCOVERED A PATHWAY, THE LOSS OF WHICH IS ASSOCIATED WITH PERSISTENT STAT3 ACTIVATION IN HUMAN CANCER. WE FOUND THAT THE GENE ENCODING THE TUMOR SUPPRESSOR MICRORNA MIR-146B IS A DIRECT STAT3 TARGET GENE, AND ITS EXPRESSION WAS INCREASED IN NORMAL BREAST EPITHELIAL CELLS BUT DECREASED IN TUMOR CELLS. METHYLATION OF THE MIR-146B PROMOTER, WHICH INHIBITED STAT3-MEDIATED INDUCTION OF EXPRESSION, WAS INCREASED IN PRIMARY BREAST CANCERS. MOREOVER, WE FOUND THAT MIR-146B INHIBITED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT PRODUCTION OF IL-6, SUBSEQUENT STAT3 ACTIVATION, AND IL-6/STAT3-DRIVEN MIGRATION AND INVASION IN BREAST CANCER CELLS, THEREBY ESTABLISHING A NEGATIVE FEEDBACK LOOP. IN ADDITION, HIGHER EXPRESSION OF MIR-146B WAS POSITIVELY CORRELATED WITH PATIENT SURVIVAL IN BREAST CANCER SUBTYPES WITH INCREASED IL6 EXPRESSION AND STAT3 PHOSPHORYLATION. OUR RESULTS IDENTIFY AN EPIGENETIC MECHANISM OF CROSSTALK BETWEEN STAT3 AND NF-KAPPAB RELEVANT TO CONSTITUTIVE STAT3 ACTIVATION IN MALIGNANCY AND THE ROLE OF INFLAMMATION IN ONCOGENESIS. 2014 9 589 24 BET BROMODOMAIN INHIBITORS SUPPRESS INFLAMMATORY ACTIVATION OF GINGIVAL FIBROBLASTS AND EPITHELIAL CELLS FROM PERIODONTITIS PATIENTS. BET BROMODOMAIN PROTEINS ARE IMPORTANT EPIGENETIC REGULATORS OF GENE EXPRESSION THAT BIND ACETYLATED HISTONE TAILS AND REGULATE THE FORMATION OF ACETYLATION-DEPENDENT CHROMATIN COMPLEXES. BET INHIBITORS SUPPRESS INFLAMMATORY RESPONSES IN MULTIPLE CELL TYPES AND ANIMAL MODELS, AND PROTECT AGAINST BONE LOSS IN EXPERIMENTAL PERIODONTITIS IN MICE. HERE, WE ANALYZED THE ROLE OF BET PROTEINS IN INFLAMMATORY ACTIVATION OF GINGIVAL FIBROBLASTS (GFS) AND GINGIVAL EPITHELIAL CELLS (GECS). WE SHOW THAT THE BET INHIBITORS I-BET151 AND JQ1 SIGNIFICANTLY REDUCED EXPRESSION AND/OR PRODUCTION OF DISTINCT, BUT OVERLAPPING, PROFILES OF CYTOKINE-INDUCIBLE MEDIATORS OF INFLAMMATION AND BONE RESORPTION IN GFS FROM HEALTHY DONORS (IL6, IL8, IL1B, CCL2, CCL5, COX2, AND MMP3) AND THE GEC LINE TIGK (IL6, IL8, IL1B, CXCL10, MMP9) WITHOUT AFFECTING CELL VIABILITY. ACTIVATION OF MITOGEN-ACTIVATED PROTEIN KINASE AND NUCLEAR FACTOR-KAPPAB PATHWAYS WAS UNAFFECTED BY I-BET151, AS WAS THE HISTONE ACETYLATION STATUS, AND NEW PROTEIN SYNTHESIS WAS NOT REQUIRED FOR THE ANTI-INFLAMMATORY EFFECTS OF BET INHIBITION. I-BET151 AND JQ1 ALSO SUPPRESSED EXPRESSION OF INFLAMMATORY CYTOKINES, CHEMOKINES, AND OSTEOCLASTOGENIC MEDIATORS IN GFS AND TIGKS INFECTED WITH THE KEY PERIODONTAL PATHOGEN PORPHYROMONAS GINGIVALIS. NOTABLY, P. GINGIVALIS INTERNALIZATION AND INTRACELLULAR SURVIVAL IN GFS AND TIGKS REMAINED UNAFFECTED BY BET INHIBITORS. FINALLY, INHIBITION OF BET PROTEINS SIGNIFICANTLY REDUCED P. GINGIVALIS-INDUCED INFLAMMATORY MEDIATOR EXPRESSION IN GECS AND GFS FROM PATIENTS WITH PERIODONTITIS. OUR RESULTS DEMONSTRATE THAT BET INHIBITORS MAY BLOCK THE EXCESSIVE INFLAMMATORY MEDIATOR PRODUCTION BY RESIDENT CELLS OF THE GINGIVAL TISSUE AND IDENTIFY THE BET FAMILY OF EPIGENETIC READER PROTEINS AS A POTENTIAL THERAPEUTIC TARGET IN THE TREATMENT OF PERIODONTAL DISEASE. 2019 10 2425 28 EPIGENETIC SILENCING OF IRF1 DYSREGULATES TYPE III INTERFERON RESPONSES TO RESPIRATORY VIRUS INFECTION IN EPITHELIAL TO MESENCHYMAL TRANSITION. CHRONIC OXIDATIVE INJURY PRODUCED BY AIRWAY DISEASE TRIGGERS A TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA)-MEDIATED EPIGENETIC REPROGRAMMING KNOWN AS THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). WE OBSERVE THAT EMT SILENCES PROTECTIVE MUCOSAL INTERFERON (IFN)-I AND III PRODUCTION ASSOCIATED WITH ENHANCED RHINOVIRUS (RV) AND RESPIRATORY SYNCYTIAL VIRUS (RSV) REPLICATION. MESENCHYMAL TRANSITIONED CELLS ARE DEFECTIVE IN INDUCIBLE INTERFERON REGULATORY FACTOR 1 (IRF1) EXPRESSION BY OCCLUDING RELA AND IRF3 ACCESS TO THE PROMOTER. IRF1 IS NECESSARY FOR THE EXPRESSION OF TYPE III IFNS (IFNLS 1 AND 2/3). INDUCED BY THE EMT, ZINC FINGER E-BOX BINDING HOMEOBOX 1 (ZEB1) BINDS AND SILENCES IRF1. ECTOPIC ZEB1 IS SUFFICIENT FOR IRF1 SILENCING, WHEREAS ZEB1 KNOCKDOWN PARTIALLY RESTORES IRF1-IFNL UPREGULATION. ZEB1 SILENCES IRF1 THROUGH THE CATALYTIC ACTIVITY OF THE ENHANCER OF ZESTE 2 POLYCOMB REPRESSIVE COMPLEX 2 SUBUNIT (EZH2), FORMING REPRESSIVE H3K27(ME3) MARKS. WE OBSERVE THAT IRF1 EXPRESSION IS MEDIATED BY ZEB1 DE-REPRESSION, AND OUR STUDY DEMONSTRATES HOW AIRWAY REMODELLING/FIBROSIS IS ASSOCIATED WITH A DEFECTIVE MUCOSAL ANTIVIRAL RESPONSE THROUGH ZEB1-INITIATED EPIGENETIC SILENCING. 2017 11 692 26 BRD4 PROMOTES HEPATIC STELLATE CELLS ACTIVATION AND HEPATIC FIBROSIS VIA MEDIATING P300/H3K27AC/PLK1 AXIS. HEPATIC FIBROSIS (HF) IS A REVERSIBLE WOUND-HEALING RESPONSE CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX (ECM) DEPOSITION AND SECONDARY TO PERSISTENT CHRONIC INJURY. BROMODOMAIN PROTEIN 4 (BRD4) COMMONLY FUNCTIONS AS A "READER" TO REGULATE EPIGENETIC MODIFICATIONS INVOLVED IN VARIOUS BIOLOGICAL AND PATHOLOGICAL EVENTS, BUT THE MECHANISM OF HF REMAINS UNCLEAR. IN THIS STUDY, WE ESTABLISHED A CCL(4)-INDUCED HF MODEL AND SPONTANEOUS RECOVERY MODEL IN MICE AND FOUND ABERRANT BRD4 EXPRESSION, WHICH WAS CONSISTENT WITH THE RESULTS IN HUMAN HEPATIC STELLATE CELLS (HSCS)- LX2 CELLS IN VITRO. SUBSEQUENTLY, WE FOUND THAT DISTRICTION AND INHIBITION OF BRD4 RESTRAINED TGFBETA-INDUCED TRANS-DIFFERENTIATION OF LX2 CELLS INTO ACTIVATED, PROLIFERATIVE MYOFIBROBLASTS AND ACCELERATED APOPTOSIS, AND BRD4 OVEREXPRESSION BLOCKED MDI-INDUCED LX2 CELLS INACTIVATION AND PROMOTED THE PROLIFERATION AND INHIBITED APOPTOSIS OF INACTIVATED CELLS. ADDITIONALLY, ADENO-ASSOCIATED VIRUS SEROTYPE 8-LOADED SHORT HAIRPIN RNA-MEDIATED BRD4 KNOCKDOWN IN MICE SIGNIFICANTLY ATTENUATED CCL(4)-INDUCED FIBROTIC RESPONSES INCLUDING HSCS ACTIVATION AND COLLAGEN DEPOSITION. MECHANISTICALLY, BRD4 DEFICIENCY INHIBITED PLK1 EXPRESSION IN ACTIVATED LX2 CELLS, AND CHIP AND CO-IP ASSAYS REVEALED THAT BRD4 REGULATION OF PLK1 WAS DEPENDENT ON P300-MEDIATED ACETYLATION MODIFICATION FOR H3K27 ON THE PLK1 PROMOTER. IN CONCLUSION, BRD4 DEFICIENCY IN THE LIVER ALLEVIATES CCL(4)-INDUCED HF IN MICE, AND BRD4 PARTICIPATES IN THE ACTIVATION AND REVERSAL OF HSCS THROUGH POSITIVELY REGULATING THE P300/H3K27AC/PLK1 AXIS, PROVIDING A POTENTIAL INSIGHT FOR HF THERAPY. 2023 12 1764 26 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 13 1632 25 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 14 5715 31 SIRT3 RESTRICTS HEPATITIS B VIRUS TRANSCRIPTION AND REPLICATION THROUGH EPIGENETIC REGULATION OF COVALENTLY CLOSED CIRCULAR DNA INVOLVING SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 AND SET DOMAIN CONTAINING 1A HISTONE METHYLTRANSFERASES. HEPATITIS B VIRUS (HBV) INFECTION REMAINS A MAJOR HEALTH PROBLEM WORLDWIDE. MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA), WHICH SERVES AS A TEMPLATE FOR HBV RNA TRANSCRIPTION, IS RESPONSIBLE FOR THE FAILURE OF ERADICATING CHRONIC HBV DURING CURRENT ANTIVIRAL THERAPY. CCCDNA IS ASSEMBLED WITH CELLULAR HISTONE PROTEINS INTO CHROMATIN, BUT LITTLE IS KNOWN ABOUT THE REGULATION OF HBV CHROMATIN BY HISTONE POSTTRANSLATIONAL MODIFICATIONS. IN THIS STUDY, WE IDENTIFIED SILENT MATING TYPE INFORMATION REGULATION 2 HOMOLOG 3 (SIRT3) AS A HOST FACTOR RESTRICTING HBV TRANSCRIPTION AND REPLICATION BY SCREENING SEVEN MEMBERS OF THE SIRTUIN FAMILY, WHICH IS THE CLASS III HISTONE DEACETYLASE. ECTOPIC SIRT3 EXPRESSION SIGNIFICANTLY REDUCED TOTAL HBV RNAS, 3.5-KB RNA, AS WELL AS REPLICATIVE INTERMEDIATE DNA IN HBV-INFECTED HEPG2-NA(+) /TAUROCHOLATE COTRANSPORTING POLYPEPTIDE CELLS AND PRIMARY HUMAN HEPATOCYTES. IN CONTRAST, GENE SILENCING OF SIRT3 PROMOTED HBV TRANSCRIPTION AND REPLICATION. A MECHANISTIC STUDY FOUND THAT NUCLEAR SIRT3 WAS RECRUITED TO THE HBV CCCDNA, WHERE IT DEACETYLATED HISTONE 3 LYSINE 9. IMPORTANTLY, OCCUPANCY OF SIRT3 ON CCCDNA COULD INCREASE THE RECRUITMENT OF HISTONE METHYLTRANSFERASE SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 TO CCCDNA AND DECREASE RECRUITMENT OF SET DOMAIN CONTAINING 1A, LEADING TO A MARKED INCREASE OF TRIMETHYL-HISTONE H3 (LYS9) AND A DECREASE OF TRIMETHYL-HISTONE H3 (LYS4) ON CCCDNA. MOREOVER, SIRT3-MEDIATED HBV CCCDNA TRANSCRIPTIONAL REPRESSION INVOLVED DECREASED BINDING OF HOST RNA POLYMERASE II AND TRANSCRIPTION FACTOR YIN YANG 1 TO CCCDNA. FINALLY, HEPATITIS B VIRAL X PROTEIN COULD RELIEVE SIRT3-MEDIATED CCCDNA TRANSCRIPTIONAL REPRESSION BY INHIBITING BOTH SIRT3 EXPRESSION AND ITS RECRUITMENT TO CCCDNA. CONCLUSION: SIRT3 IS A HOST FACTOR EPIGENETICALLY RESTRICTING HBV CCCDNA TRANSCRIPTION BY ACTING COOPERATIVELY WITH HISTONE METHYLTRANSFERASE; THESE DATA PROVIDE A RATIONALE FOR THE USE OF SIRT3 ACTIVATORS IN THE PREVENTION OR TREATMENT OF HBV INFECTION. (HEPATOLOGY 2018). 2018 15 1906 31 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 16 3373 27 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018 17 1945 28 EPIGALLOCATECHIN-3-GALLATE, A HISTONE ACETYLTRANSFERASE INHIBITOR, INHIBITS EBV-INDUCED B LYMPHOCYTE TRANSFORMATION VIA SUPPRESSION OF RELA ACETYLATION. BECAUSE THE P300/CBP-MEDIATED HYPERACETYLATION OF RELA (P65) IS CRITICAL FOR NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) ACTIVATION, THE ATTENUATION OF P65 ACETYLATION IS A POTENTIAL MOLECULAR TARGET FOR THE PREVENTION OF CHRONIC INFLAMMATION. DURING OUR ONGOING SCREENING STUDY TO IDENTIFY NATURAL COMPOUNDS WITH HISTONE ACETYLTRANSFERASE INHIBITOR (HATI) ACTIVITY, WE IDENTIFIED EPIGALLOCATECHIN-3-GALLATE (EGCG) AS A NOVEL HATI WITH GLOBAL SPECIFICITY FOR THE MAJORITY OF HAT ENZYMES BUT WITH NO ACTIVITY TOWARD EPIGENETIC ENZYMES INCLUDING HDAC, SIRT1, AND HMTASE. AT A DOSE OF 100 MICROMOL/L, EGCG ABROGATES P300-INDUCED P65 ACETYLATION IN VITRO AND IN VIVO, INCREASES THE LEVEL OF CYTOSOLIC IKAPPABALPHA, AND SUPPRESSES TUMOR NECROSIS FACTOR ALPHA (TNFALPHA)-INDUCED NF-KAPPAB ACTIVATION. WE ALSO SHOWED THAT EGCG PREVENTS TNFALPHA-INDUCED P65 TRANSLOCATION TO THE NUCLEUS, CONFIRMING THAT HYPERACETYLATION IS CRITICAL FOR NF-KAPPAB TRANSLOCATION AS WELL AS ACTIVITY. FURTHERMORE, EGCG TREATMENT INHIBITED THE ACETYLATION OF P65 AND THE EXPRESSION OF NF-KAPPAB TARGET GENES IN RESPONSE TO DIVERSE STIMULI. FINALLY, EGCG REDUCED THE BINDING OF P300 TO THE PROMOTER REGION OF INTERLEUKIN-6 GENE WITH AN INCREASED RECRUITMENT OF HDAC3, WHICH HIGHLIGHTS THE IMPORTANCE OF THE BALANCE BETWEEN HATS AND HISTONE DEACETYLASES IN THE NF-KAPPAB-MEDIATED INFLAMMATORY SIGNALING PATHWAY. IMPORTANTLY, EGCG AT 50 MICROMOL/L DOSE COMPLETELY BLOCKS EBV INFECTION-INDUCED CYTOKINE EXPRESSION AND SUBSEQUENTLY THE EBV-INDUCED B LYMPHOCYTE TRANSFORMATION. THESE RESULTS SHOW THE CRUCIAL ROLE OF ACETYLATION IN THE DEVELOPMENT OF INFLAMMATORY-RELATED DISEASES. 2009 18 3767 23 INTEGRATIVE EPIGENOMIC ANALYSIS IN DIFFERENTIATED HUMAN PRIMARY BRONCHIAL EPITHELIAL CELLS EXPOSED TO CIGARETTE SMOKE. CIGARETTE SMOKE (CS) IS ONE OF THE MAJOR RISK FACTORS FOR MANY PULMONARY DISEASES, INCLUDING CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND LUNG CANCER. THE FIRST LINE OF DEFENSE FOR CS EXPOSURE IS THE BRONCHIAL EPITHELIAL CELLS. ELUCIDATION OF THE EPIGENETIC CHANGES DURING CS EXPOSURE IS KEY TO GAINING A MECHANISTIC UNDERSTANDING INTO HOW MATURE AND DIFFERENTIATED BRONCHIAL EPITHELIAL CELLS RESPOND TO CS. THEREFORE, WE PERFORMED EPIGENOMIC PROFILING IN CONJUNCTION WITH TRANSCRIPTIONAL PROFILING IN WELL-DIFFERENTIATED HUMAN BRONCHIAL EPITHELIAL (HBE) CELLS CULTURED IN AIR-LIQUID INTERFACE (ALI) EXPOSED TO THE VAPOR PHASE OF CS. THE GENOME-WIDE ENRICHMENT OF HISTONE 3 LYSINE 27 ACETYLATION WAS DETECTED BY CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY NEXT GENERATION SEQUENCING (CHIP-SEQ) IN HBE CELLS AND SUGGESTED THE PLAUSIBLE BINDING OF SPECIFIC TRANSCRIPTION FACTORS RELATED TO CS EXPOSURE. ADDITIONALLY, INTERROGATION OF CHIP-SEQ DATA WITH GENE EXPRESSION PROFILING OF HBE CELLS AFTER CS EXPOSURE FOR DIFFERENT DURATIONS (3 HOURS, 2 DAYS, 4 DAYS) SUGGESTED THAT EARLIER EPIGENETIC CHANGES (3 HOURS AFTER CS EXPOSURE) MAY BE ASSOCIATED WITH LATER GENE EXPRESSION CHANGES INDUCED BY CS EXPOSURE (4 DAYS). THE INTEGRATION OF EPIGENETICS AND GENE EXPRESSION DATA REVEALED SIGNALING PATHWAYS RELATED TO CS-INDUCED EPIGENETIC CHANGES IN HBE CELLS THAT MAY IDENTIFY NOVEL REGULATORY PATHWAYS RELATED TO CS-INDUCED COPD. 2018 19 2889 26 GAIN-OF-FUNCTION STAT1 MUTATIONS IMPAIR STAT3 ACTIVITY IN PATIENTS WITH CHRONIC MUCOCUTANEOUS CANDIDIASIS (CMC). SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) TRIGGERED PRODUCTION OF TH-17 CYTOKINES MEDIATES PROTECTIVE IMMUNITY AGAINST FUNGI. MUTATIONS AFFECTING THE STAT3/INTERLEUKIN 17 (IL-17) PATHWAY CAUSE SELECTIVE SUSCEPTIBILITY TO FUNGAL (CANDIDA) INFECTIONS, A HALLMARK OF CHRONIC MUCOCUTANEOUS CANDIDIASIS (CMC). IN PATIENTS WITH AUTOSOMAL DOMINANT CMC, WE AND OTHERS PREVIOUSLY REPORTED DEFECTIVE TH17 RESPONSES AND UNDERLYING GAIN-OF-FUNCTION (GOF) STAT1 MUTATIONS, BUT HOW THIS AFFECTS STAT3 FUNCTION LEADING TO DECREASED IL-17 IS UNCLEAR. WE ALSO ASSESSED HOW GOF-STAT1 MUTATIONS AFFECT STAT3 ACTIVATION, DNA BINDING, GENE EXPRESSION, CYTOKINE PRODUCTION, AND EPIGENETIC MODIFICATIONS. WE EXCLUDED IMPAIRED STAT3 PHOSPHORYLATION, NUCLEAR TRANSLOCATION, AND SEQUESTRATION OF STAT3 INTO STAT1/STAT3 HETERODIMERS AND CONFIRM SIGNIFICANTLY REDUCED TRANSCRIPTION OF STAT3-INDUCIBLE GENES (RORC/IL-17/IL-22/IL-10/C-FOS/SOCS3/C-MYC) AS LIKELY UNDERLYING MECHANISM. STAT BINDING TO THE HIGH AFFINITY SIS-INDUCIBLE ELEMENT WAS INTACT BUT BINDING TO AN ENDOGENOUS STAT3 DNA TARGET WAS IMPAIRED. REDUCED STAT3-DEPENDENT GENE TRANSCRIPTION WAS REVERSED BY INHIBITING STAT1 ACTIVATION WITH FLUDARABINE OR ENHANCING HISTONE, BUT NOT STAT1 OR STAT3 ACETYLATION WITH HISTONE DEACETYLASE (HDAC) INHIBITORS TRICHOSTATIN A OR ITF2357. SILENCING HDAC1, HDAC2, AND HDAC3 INDICATED A ROLE FOR HDAC1 AND 2. REDUCED STAT3-DEPENDENT GENE TRANSCRIPTION UNDERLIES LOW TH-17 RESPONSES IN GOF-STAT1 CMC, WHICH CAN BE REVERSED BY INHIBITING ACETYLATION, OFFERING NOVEL TARGETS FOR FUTURE THERAPIES. 2015 20 5226 27 PRMT5 RESTRICTS HEPATITIS B VIRUS REPLICATION THROUGH EPIGENETIC REPRESSION OF COVALENTLY CLOSED CIRCULAR DNA TRANSCRIPTION AND INTERFERENCE WITH PREGENOMIC RNA ENCAPSIDATION. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION REMAINS A MAJOR HEALTH PROBLEM WORLDWIDE. THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) MINICHROMOSOME, WHICH SERVES AS THE TEMPLATE FOR THE TRANSCRIPTION OF VIRAL RNAS, PLAYS A KEY ROLE IN VIRAL PERSISTENCE. WHILE ACCUMULATING EVIDENCE SUGGESTS THAT CCCDNA TRANSCRIPTION IS REGULATED BY EPIGENETIC MACHINERY, PARTICULARLY THE ACETYLATION OF CCCDNA-BOUND HISTONE 3 (H3) AND H4, THE POTENTIAL CONTRIBUTIONS OF HISTONE METHYLATION AND RELATED HOST FACTORS REMAIN OBSCURE. HERE, BY SCREENING A SERIES OF METHYLTRANSFERASES AND DEMETHYLASES, WE IDENTIFIED PROTEIN ARGININE METHYLTRANSFERASE 5 (PRMT5) AS AN EFFECTIVE RESTRICTOR OF HBV TRANSCRIPTION AND REPLICATION. IN CELL CULTURE-BASED MODELS FOR HBV INFECTION AND IN LIVER TISSUES OF PATIENTS WITH CHRONIC HBV INFECTION, WE FOUND THAT SYMMETRIC DIMETHYLATION OF ARGININE 3 ON H4 ON CCCDNA WAS A REPRESSIVE MARKER OF CCCDNA TRANSCRIPTION AND WAS REGULATED BY PRMT5 DEPENDING ON ITS METHYLTRANSFERASE DOMAIN. MOREOVER, PRMT5-TRIGGERED SYMMETRIC DIMETHYLATION OF ARGININE 3 ON H4 ON THE CCCDNA MINICHROMOSOME INVOLVED AN INTERACTION WITH THE HBV CORE PROTEIN AND THE BRG1-BASED HUMAN SWI/SNF CHROMATIN REMODELER, WHICH RESULTED IN DOWN-REGULATION OF THE BINDING OF RNA POLYMERASE II TO CCCDNA. IN ADDITION TO THE INHIBITORY EFFECT ON CCCDNA TRANSCRIPTION, PRMT5 INHIBITED HBV CORE PARTICLE DNA PRODUCTION INDEPENDENTLY OF ITS METHYLTRANSFERASE ACTIVITY. FURTHER STUDY REVEALED THAT PRMT5 INTERFERED WITH PREGENOMIC RNA ENCAPSIDATION BY PREVENTING ITS INTERACTION WITH VIRAL POLYMERASE PROTEIN THROUGH BINDING TO THE REVERSE TRANSCRIPTASE-RIBONUCLEASE H REGION OF POLYMERASE, WHICH IS CRUCIAL FOR THE POLYMERASE-PREGENOMIC RNA INTERACTION. CONCLUSION: PRMT5 RESTRICTS HBV REPLICATION THROUGH A TWO-PART MECHANISM INCLUDING EPIGENETIC SUPPRESSION OF CCCDNA TRANSCRIPTION AND INTERFERENCE WITH PREGENOMIC RNA ENCAPSIDATION; THESE FINDINGS IMPROVE THE UNDERSTANDING OF EPIGENETIC REGULATION OF HBV TRANSCRIPTION AND HOST-HBV INTERACTION, THUS PROVIDING NEW INSIGHTS INTO TARGETED THERAPEUTIC INTERVENTION. (HEPATOLOGY 2017;66:398-415). 2017