1 972 143 CHRONIC OBSTRUCTIVE PULMONARY DISEASE IS ASSOCIATED WITH EPIGENOME-WIDE DIFFERENTIAL METHYLATION IN BAL LUNG CELLS. DNA METHYLATION PATTERNS IN CHRONIC PULMONARY OBSTRUCTIVE DISEASE (COPD) MIGHT OFFER NEW INSIGHTS INTO DISEASE PATHOGENESIS. TO ASSESS METHYLATION PROFILES IN THE MAIN COPD TARGET ORGAN, WE PERFORMED AN EPIGENOME-WIDE ASSOCIATION STUDY ON BAL CELLS. BRONCHOSCOPIES WERE PERFORMED IN 18 SUBJECTS WITH COPD AND 15 CONTROL SUBJECTS (EX- AND CURRENT SMOKERS). DNA METHYLATION WAS MEASURED USING THE ILLUMINA METHYLATIONEPIC BEADCHIP KIT, COVERING MORE THAN 850,000 CPGS. DIFFERENTIALLY METHYLATED POSITIONS (DMPS) WERE EXAMINED FOR 1) ENRICHMENT IN PATHWAYS AND FUNCTIONAL GENE RELATIONSHIPS USING THE KYOTO ENCYCLOPEDIA OF GENES AND GENOMES AND GENE ONTOLOGY, 2) ACCELERATED AGING USING HORVATH'S EPIGENETIC CLOCK, 3) CORRELATION WITH GENE EXPRESSION, AND 4) COLOCALIZATION WITH GENETIC VARIATION. WE FOUND 1,155 BONFERRONI-SIGNIFICANT (P < 6.74 X 10(-8)) DMPS ASSOCIATED WITH COPD, MANY WITH LARGE EFFECT SIZES. FUNCTIONAL ANALYSIS IDENTIFIED BIOLOGICALLY PLAUSIBLE PATHWAYS AND GENE RELATIONSHIPS, INCLUDING ENRICHMENT FOR TRANSCRIPTION FACTOR ACTIVITY. STRONG CORRELATION WAS FOUND BETWEEN DNA METHYLATION AND CHRONOLOGICAL AGE BUT NOT BETWEEN COPD AND ACCELERATED AGING. FOR 79 UNIQUE DMPS, DNA METHYLATION CORRELATED SIGNIFICANTLY WITH GENE EXPRESSION IN BAL CELLS. THIRTY-NINE PERCENT OF DMPS WERE COLOCALIZED WITH COPD-ASSOCIATED SNPS. TO THE BEST OF OUR KNOWLEDGE, THIS IS THE FIRST EPIGENOME-WIDE ASSOCIATION STUDY OF COPD ON BAL CELLS, AND OUR ANALYSES REVEALED MANY DIFFERENTIAL METHYLATION SITES. INTEGRATION WITH MRNA DATA SHOWED A STRONG FUNCTIONAL READOUT FOR RELEVANT GENES, IDENTIFYING SITES WHERE DNA METHYLATION MIGHT DIRECTLY AFFECT EXPRESSION. ALMOST HALF OF DMPS WERE COLOCATED WITH SNPS IDENTIFIED IN PREVIOUS GENOME-WIDE ASSOCIATION STUDIES OF COPD, SUGGESTING JOINT GENETIC AND EPIGENETIC PATHWAYS RELATED TO DISEASE. 2022 2 3634 34 INCREASED CD4(+) T CELL LINEAGE COMMITMENT DETERMINED BY CPG METHYLATION CORRELATES WITH BETTER PROGNOSIS IN URINARY BLADDER CANCER PATIENTS. BACKGROUND: URINARY BLADDER CANCER IS A COMMON MALIGNANCY WORLDWIDE. ENVIRONMENTAL FACTORS AND CHRONIC INFLAMMATION ARE CORRELATED WITH THE DISEASE RISK. DIAGNOSIS IS PERFORMED BY TRANSURETHRAL RESECTION OF THE BLADDER, AND PATIENTS WITH MUSCLE INVASIVE DISEASE PREFERABLY PROCEED TO RADICAL CYSTECTOMY, WITH OR WITHOUT NEOADJUVANT CHEMOTHERAPY. THE ANTI-TUMOUR IMMUNE RESPONSES, KNOWN TO BE INITIATED IN THE TUMOUR AND DRAINING LYMPH NODES, MAY PLAY A MAJOR ROLE IN FUTURE TREATMENT STRATEGIES. THUS, INCREASING THE KNOWLEDGE OF TUMOUR-ASSOCIATED IMMUNOLOGICAL PROCESSES IS IMPORTANT. ACTIVATED CD4(+) T CELLS DIFFERENTIATE INTO FOUR MAIN SEPARATE LINEAGES: TH1, TH2, TH17 AND TREG, AND THEY ARE RECOGNIZED BY THEIR EFFECTOR MOLECULES IFN-GAMMA, IL-13, IL-17A, AND THE TRANSCRIPTION FACTOR FOXP3, RESPECTIVELY. WE HAVE PREVIOUSLY DEMONSTRATED SIGNATURE CPG SITES PREDICTIVE FOR LINEAGE COMMITMENT OF THESE FOUR MAJOR CD4(+) T CELL LINEAGES. HERE, WE INVESTIGATE THE LINEAGE COMMITMENT SPECIFICALLY IN TUMOUR, LYMPH NODES AND BLOOD AND RELATE THEM TO THE DISEASE STAGE AND RESPONSE TO NEOADJUVANT CHEMOTHERAPY. RESULTS: BLOOD, TUMOUR AND REGIONAL LYMPH NODES WERE OBTAINED FROM PATIENTS AT TIME OF TRANSURETHRAL RESECTION OF THE BLADDER AND AT RADICAL CYSTECTOMY. TUMOUR-INFILTRATING CD4(+) LYMPHOCYTES WERE SIGNIFICANTLY HYPOMETHYLATED IN ALL FOUR INVESTIGATED LINEAGE LOCI COMPARED TO CD4(+) LYMPHOCYTES IN LYMPH NODES AND BLOOD (LYMPH NODES VS TUMOUR-INFILTRATING LYMPHOCYTES: IFNG -4229 BP P < 0.0001, IL13 -11 BP P < 0.05, IL17A -122 BP P < 0.01 AND FOXP3 -77 BP P > 0.05). EXAMINATION OF INDIVIDUAL LYMPH NODES DISPLAYED DIFFERENT METHYLATION SIGNATURES, SUGGESTING POSSIBLE CORRELATION WITH FUTURE SURVIVAL. MORE ADVANCED POST-CYSTECTOMY TUMOUR STAGES CORRELATED SIGNIFICANTLY WITH INCREASED METHYLATION AT THE IFNG -4229 BP LOCUS. PATIENTS WITH COMPLETE RESPONSE TO NEOADJUVANT CHEMOTHERAPY DISPLAYED SIGNIFICANT HYPOMETHYLATION IN CD4(+) T CELLS FOR ALL FOUR INVESTIGATED LOCI, MOST PROMINENTLY IN IFNG P < 0.0001. NEOADJUVANT CHEMOTHERAPY SEEMED TO RESULT IN A RELOCATION OF TH1-COMMITTED CD4(+) T CELLS FROM BLOOD, PRESUMABLY TO THE TUMOUR, INDICATED BY SHIFTS IN THE METHYLATION PATTERNS, WHEREAS NO SUCH SHIFTS WERE SEEN FOR LINEAGES CORRESPONDING TO IL13, IL17A AND FOXP3. CONCLUSION: INCREASED LINEAGE COMMITMENT IN CD4(+) T CELLS, AS DETERMINED BY DEMETHYLATION IN PREDICTIVE CPG SITES, IS ASSOCIATED WITH LOWER POST-CYSTECTOMY TUMOUR STAGE, COMPLETE RESPONSE TO NEOADJUVANT CHEMOTHERAPY AND OVERALL BETTER OUTCOME, SUGGESTING EPIGENETIC PROFILING OF CD4(+) T CELL LINEAGES AS A USEFUL READOUT FOR CLINICAL STAGING. 2018 3 64 35 A HIGH-THROUGHPUT SCREENING ASSAY FOR SILENCING ESTABLISHED HIV-1 MACROPHAGE INFECTION IDENTIFIES NUCLEOSIDE ANALOGS THAT PERTURB H3K9ME3 ON PROVIRAL GENOMES. HIV-INFECTED MACROPHAGES ARE LONG-LIVED CELLS THAT REPRESENT A BARRIER TO FUNCTIONAL CURE. ADDITIONALLY, LOW-LEVEL VIRAL EXPRESSION BY CENTRAL NERVOUS SYSTEM (CNS) MACROPHAGES CONTRIBUTES TO NEUROCOGNITIVE DEFICITS THAT DEVELOP DESPITE ANTIRETROVIRAL THERAPY (ART). WE RECENTLY IDENTIFIED H3K9ME3 AS AN ATYPICAL EPIGENETIC MARK ASSOCIATED WITH CHRONIC HIV INFECTION IN MACROPHAGES. THUS, STRATEGIES ARE NEEDED TO SUPPRESS HIV-1 EXPRESSION IN MACROPHAGES, BUT THE UNIQUE MYELOID ENVIRONMENT AND THE RESPONSIBLE MACROPHAGE/CNS-TROPIC STRAINS REQUIRE CELL/STRAIN-SPECIFIC APPROACHES. HERE, WE GENERATED AN HIV-1 REPORTER VIRUS FROM A CNS-DERIVED STRAIN WITH INTACT AUXILIARY GENES EXPRESSING DESTABILIZED LUCIFERASE. WE EMPLOYED THIS REPORTER VIRUS IN POLYCLONAL INFECTION OF PRIMARY HUMAN MONOCYTE-DERIVED MACROPHAGES (MDM) FOR A HIGH-THROUGHPUT SCREEN (HTS) TO IDENTIFY COMPOUNDS THAT SUPPRESS VIRUS EXPRESSION FROM ESTABLISHED MACROPHAGE INFECTION. SCREENING ~6,000 KNOWN DRUGS AND COMPOUNDS YIELDED 214 HITS. A SECONDARY SCREEN WITH 10-DOSE TITRATION IDENTIFIED 24 MEETING CRITERIA FOR HIV-SELECTIVE ACTIVITY. USING THREE REPLICATION-COMPETENT CNS-DERIVED MACROPHAGE-TROPIC HIV-1 ISOLATES AND VIRAL GENE EXPRESSION READOUT IN MDM, WE CONFIRMED THE EFFECT OF THREE PURINE ANALOGS, NELARABINE, FLUDARABINE, AND ENTECAVIR, SHOWING THE SUPPRESSION OF HIV-1 EXPRESSION FROM ESTABLISHED MACROPHAGE INFECTION. NELARABINE INHIBITED THE FORMATION OF H3K9ME3 ON HIV GENOMES IN MACROPHAGES. THUS, THIS NOVEL HTS ASSAY CAN IDENTIFY SUPPRESSORS OF HIV-1 TRANSCRIPTION IN ESTABLISHED MACROPHAGE INFECTION, SUCH AS NUCLEOSIDE ANALOGS AND HDAC INHIBITORS, WHICH MAY BE LINKED TO H3K9ME3 MODIFICATION. THIS SCREEN MAY BE USEFUL TO IDENTIFY NEW METABOLIC AND EPIGENETIC AGENTS THAT AMELIORATE HIV-DRIVEN NEUROINFLAMMATION IN PEOPLE ON ART OR PREVENT VIRAL RECRUDESCENCE FROM MACROPHAGE RESERVOIRS IN STRATEGIES TO ACHIEVE ART-FREE REMISSION. IMPORTANCE MACROPHAGES INFECTED BY HIV-1 ARE A LONG-LIVED RESERVOIR AND A BARRIER IN CURRENT EFFORTS TO ACHIEVE HIV CURE AND ALSO CONTRIBUTE TO NEUROCOGNITIVE COMPLICATIONS IN PEOPLE DESPITE ANTIRETROVIRAL THERAPY (ART). SILENCING HIV EXPRESSION IN THESE CELLS WOULD BE OF GREAT VALUE, BUT THE REGULATION OF HIV-1 IN MACROPHAGES DIFFERS FROM T CELLS. WE DEVELOPED A NOVEL HIGH-THROUGHPUT SCREEN FOR COMPOUNDS THAT CAN SILENCE ESTABLISHED INFECTION OF PRIMARY MACROPHAGES, AND IDENTIFIED AGENTS THAT DOWNREGULATE VIRUS EXPRESSION AND ALTER PROVIRUS EPIGENETIC PROFILES. THE SIGNIFICANCE OF THIS ASSAY IS THE POTENTIAL TO IDENTIFY NEW DRUGS THAT ACT IN THE UNIQUE MACROPHAGE ENVIRONMENT ON RELEVANT VIRAL STRAINS, WHICH MAY CONTRIBUTE TO ADJUNCTIVE TREATMENT FOR HIV-ASSOCIATED NEUROCOGNITIVE DISORDERS AND/OR PREVENT VIRAL REBOUND IN EFFORTS TO ACHIEVE ART-FREE REMISSION OR CURE. 2023 4 6403 29 THE ROLES OF INDUCIBLE CHROMATIN AND TRANSCRIPTIONAL MEMORY IN CELLULAR DEFENSE SYSTEM RESPONSES TO REDOX-ACTIVE POLLUTANTS. PEOPLE ARE EXPOSED TO WIDE RANGE OF REDOX-ACTIVE ENVIRONMENTAL POLLUTANTS. AIR POLLUTION, HEAVY METALS, PESTICIDES, AND ENDOCRINE DISRUPTING CHEMICALS CAN DISRUPT CELLULAR REDOX STATUS. REDOX-ACTIVE POLLUTANTS IN OUR ENVIRONMENT ALL TRIGGER THEIR OWN SETS OF SPECIFIC CELLULAR RESPONSES, BUT THEY ALSO ACTIVATE A COMMON SET OF GENERAL STRESS RESPONSES THAT BUFFER THE CELL AGAINST HOMEOSTATIC INSULTS. THESE CELLULAR DEFENSE SYSTEM (CDS) PATHWAYS INCLUDE THE HEAT SHOCK RESPONSE, THE OXIDATIVE STRESS RESPONSE, THE HYPOXIA RESPONSE, THE UNFOLDED PROTEIN RESPONSE, THE DNA DAMAGE RESPONSE, AND THE GENERAL STRESS RESPONSE MEDIATED BY THE STRESS-ACTIVATED P38 MITOGEN-ACTIVATED PROTEIN KINASE. OVER THE PAST TWO DECADES, THE FIELD OF ENVIRONMENTAL EPIGENETICS HAS INVESTIGATED EPIGENETIC RESPONSES TO ENVIRONMENTAL POLLUTANTS, INCLUDING REDOX-ACTIVE POLLUTANTS. STUDIES OF THESE RESPONSES HIGHLIGHT THE ROLE OF CHROMATIN MODIFICATIONS IN CONTROLLING THE TRANSCRIPTIONAL RESPONSE TO POLLUTANTS AND THE ROLE OF TRANSCRIPTIONAL MEMORY, OFTEN REFERRED TO AS "EPIGENETIC REPROGRAMMING", IN PREDISPOSING PREVIOUSLY EXPOSED INDIVIDUALS TO MORE POTENT TRANSCRIPTIONAL RESPONSES ON SECONDARY CHALLENGE. MY CENTRAL THESIS IN THIS REVIEW IS THAT HIGH DOSE OR CHRONIC EXPOSURE TO REDOX-ACTIVE POLLUTANTS LEADS TO TRANSCRIPTIONAL MEMORIES AT CDS TARGET GENES THAT INFLUENCE THE CELL'S ABILITY TO MOUNT PROTECTIVE RESPONSES. TO SUPPORT THIS THESIS, I WILL: (1) SUMMARIZE THE KNOWN CHROMATIN FEATURES REQUIRED FOR INDUCIBLE GENE ACTIVATION; (2) REVIEW THE KNOWN FORMS OF TRANSCRIPTIONAL MEMORY; (3) DISCUSS THE ROLES OF INDUCIBLE CHROMATIN AND TRANSCRIPTIONAL MEMORY IN CDS RESPONSES THAT ARE ACTIVATED BY REDOX-ACTIVE ENVIRONMENTAL POLLUTANTS; AND (4) PROPOSE A CONCEPTUAL FRAMEWORK FOR CDS PATHWAY RESPONSIVENESS AS A READOUT OF TOTAL CELLULAR EXPOSURE TO REDOX-ACTIVE POLLUTANTS. 2021 5 6523 30 TRANSCRIPTIONAL AND EPIGENETIC REGULATORY MECHANISMS AFFECTING HTLV-1 PROVIRUS. HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-1) IS A RETROVIRUS ASSOCIATED WITH HUMAN DISEASES, SUCH AS ADULT T-CELL LEUKEMIA (ATL) AND HTLV-1-ASSOCIATED MYELOPATHY/TROPIC SPASTIC PARAPARESIS (HAM/TSP). AS A RETROVIRUS, ITS LIFE CYCLE INCLUDES A STEP WHERE HTLV-1 IS INTEGRATED INTO THE HOST GENOMIC DNA AND FORMS PROVIRAL DNA. IN THE CHRONIC PHASE OF THE INFECTION, HTLV?1 IS KNOWN TO PROLIFERATE AS A PROVIRUS VIA THE MITOTIC DIVISION OF THE INFECTED HOST CELLS. THERE ARE GENERALLY TENS OF THOUSANDS OF INFECTED CLONES WITHIN AN INFECTED INDIVIDUAL. THEY EXIST NOT ONLY IN PERIPHERAL BLOOD, BUT ALSO IN VARIOUS LYMPHOID ORGANS. VIRAL PROTEINS ENCODED IN HTLV-1 GENOME PLAY A ROLE IN THE PROLIFERATION AND SURVIVAL OF THE INFECTED CELLS. AS IS THE CASE WITH OTHER CHRONIC VIRAL INFECTIONS, HTLV-1 GENE EXPRESSION INDUCES THE ACTIVATION OF THE HOST IMMUNITY AGAINST THE VIRUS. THUS, THE TRANSCRIPTION FROM HTLV-1 PROVIRUS NEEDS TO BE CONTROLLED IN ORDER TO EVADE THE HOST IMMUNE SURVEILLANCE. THERE SHOULD BE A DYNAMIC AND COMPLEX REGULATION IN VIVO, WHERE AN EQUILIBRIUM BETWEEN VIRAL ANTIGEN EXPRESSION AND HOST IMMUNE SURVEILLANCE IS ACHIEVED. THE MECHANISMS REGULATING VIRAL GENE EXPRESSION FROM THE PROVIRUS ARE A KEY TO UNDERSTANDING THE PERSISTENT/LATENT INFECTION WITH HTLV-1 AND ITS PATHOGENESIS. IN THIS ARTICLE, WE WOULD LIKE TO REVIEW OUR CURRENT UNDERSTANDING ON THIS TOPIC. 2016 6 4055 34 MAPPING OF HISTONE MODIFICATIONS IN EPISOMAL HBV CCCDNA UNCOVERS AN UNUSUAL CHROMATIN ORGANIZATION AMENABLE TO EPIGENETIC MANIPULATION. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION AFFECTS 240 MILLION PEOPLE WORLDWIDE AND IS A MAJOR RISK FACTOR FOR LIVER FAILURE AND HEPATOCELLULAR CARCINOMA. CURRENT ANTIVIRAL THERAPY INHIBITS CYTOPLASMIC HBV GENOMIC REPLICATION, BUT IS NOT CURATIVE BECAUSE IT DOES NOT DIRECTLY AFFECT NUCLEAR HBV CLOSED CIRCULAR DNA (CCCDNA), THE GENOMIC FORM THAT TEMPLATES VIRAL TRANSCRIPTION AND SUSTAINS VIRAL PERSISTENCE. NOVEL APPROACHES THAT DIRECTLY TARGET CCCDNA REGULATION WOULD THEREFORE BE HIGHLY DESIRABLE. CCCDNA IS ASSEMBLED WITH CELLULAR HISTONE PROTEINS INTO CHROMATIN, BUT LITTLE IS KNOWN ABOUT THE REGULATION OF HBV CHROMATIN BY HISTONE POSTTRANSLATIONAL MODIFICATIONS (PTMS). HERE, USING A NEW CCCDNA CHIP-SEQ APPROACH, WE REPORT, TO OUR KNOWLEDGE, THE FIRST GENOME-WIDE MAPS OF PTMS IN CCCDNA-CONTAINING CHROMATIN FROM DE NOVO INFECTED HEPG2 CELLS, PRIMARY HUMAN HEPATOCYTES, AND FROM HBV-INFECTED LIVER TISSUE. WE FIND HIGH LEVELS OF PTMS ASSOCIATED WITH ACTIVE TRANSCRIPTION ENRICHED AT SPECIFIC SITES WITHIN THE HBV GENOME AND, SURPRISINGLY, VERY LOW LEVELS OF PTMS LINKED TO TRANSCRIPTIONAL REPRESSION EVEN AT SILENT HBV PROMOTERS. WE SHOW THAT TRANSCRIPTION AND ACTIVE PTMS IN HBV CHROMATIN ARE REDUCED BY THE ACTIVATION OF AN INNATE IMMUNITY PATHWAY, AND THAT THIS EFFECT CAN BE RECAPITULATED WITH A SMALL MOLECULE EPIGENETIC MODIFYING AGENT, OPENING THE POSSIBILITY THAT CHROMATIN-BASED REGULATION OF CCCDNA TRANSCRIPTION COULD BE A NEW THERAPEUTIC APPROACH TO CHRONIC HBV INFECTION. 2015 7 3185 28 HBC BINDS TO THE CPG ISLANDS OF HBV CCCDNA AND PROMOTES AN EPIGENETIC PERMISSIVE STATE. HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IS THE TEMPLATE FOR THE TRANSCRIPTION OF HBV. HBV CORE PROTEIN (HBC) IS A MAIN COMPONENT OF THE HBV CCCDNA MINICHROMOSOME. HOWEVER, THE FUNCTION OF HBC IN CCCDNA IS NOT FULLY UNDERSTOOD. IN LIGHT OF RECENT FINDINGS THAT HBV CCCDNA MAY BE REGULATED EPIGENETICALLY, WE ANALYZED THE BINDING OF HBC TO CCCDNA AND THE IMPACT OF HBC ON CCCDNA EPIGENETIC PROFILE IN THE LIVER BIOPSY SAMPLES OF 22 PATIENTS WITH CHRONIC HEPATITIS B (CHB). WE FOUND THAT HBC BINDING TO HBV CCCDNA OCCURRED PREFERENTIALLY AT CPG ISLAND 2, AN IMPORTANT REGION FOR THE REGULATION OF HBV TRANSCRIPTION. FURTHERMORE, THE RELATIVE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 WERE POSITIVELY CORRELATED WITH THE RATIOS OF RELAXED CIRCULAR DNA TO CCCDNA AND THE LEVELS OF SERUM HBV DNA IN THOSE PATIENTS. INTERESTINGLY, THE RELATIVE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 WERE ASSOCIATED WITH THE BINDING OF CREB BINDING PROTEIN (CBP) AND WITH HYPOMETHYLATION IN CPG ISLAND 2 OF HBV CCCDNA MINICHROMOSOMES. HOWEVER, RELATIVELY HIGHER AMOUNTS OF HBC BINDING TO CPG ISLAND 2 OF CCCDNA WERE ACCOMPANIED BY LOWER AMOUNTS OF HDAC1 BINDING. MULTIVARIATE ANALYSIS REVEALED THAT THE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 OF CCCDNA AND POSITIVE HBEAG WERE INDEPENDENT FACTORS ASSOCIATED WITH THE REPLICATION OF HBV (P = 0.001 FOR BOTH). APPARENTLY, HBC IS A POSITIVE REGULATOR OF HBV TRANSCRIPTION AND REPLICATION, MAINTAINING THE PERMISSIVE EPIGENETIC STATE IN THE CRITICAL REGION OF THE HBV CCCDNA MINICHROMOSOMES. 2011 8 5715 34 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 9 2406 37 EPIGENETIC RESPONSES TO RHINOVIRUS EXPOSURE IN AIRWAY EPITHELIAL CELLS ARE CORRELATED WITH KEY TRANSCRIPTIONAL PATHWAYS IN CHRONIC RHINOSINUSITIS. BACKGROUND: VIRUSES MAY DRIVE IMMUNE MECHANISMS RESPONSIBLE FOR CHRONIC RHINOSINUSITIS WITH NASAL POLYPOSIS (CRSWNP), BUT LITTLE IS KNOWN ABOUT THE UNDERLYING MOLECULAR MECHANISMS. OBJECTIVES: TO IDENTIFY EPIGENETIC AND TRANSCRIPTIONAL RESPONSES TO A COMMON UPPER RESPIRATORY PATHOGEN, RHINOVIRUS (RV), THAT ARE SPECIFIC TO PATIENTS WITH CRSWNP USING A PRIMARY SINONASAL EPITHELIAL CELL CULTURE MODEL. METHODS: AIRWAY EPITHELIAL CELLS WERE COLLECTED AT SURGERY FROM PATIENTS WITH CRSWNP (CASES) AND FROM CONTROLS WITHOUT SINUS DISEASE, CULTURED, AND THEN EXPOSED TO RV OR VEHICLE FOR 48 H. DIFFERENTIAL GENE EXPRESSION AND DNA METHYLATION (DNAM) BETWEEN CASES AND CONTROLS IN RESPONSE TO RV WERE DETERMINED USING LINEAR MIXED MODELS. WEIGHTED GENE CO-EXPRESSION ANALYSIS (WGCNA) WAS USED TO IDENTIFY (A) CO-REGULATED GENE EXPRESSION AND DNAM SIGNATURES, AND (B) GENES, PATHWAYS, AND REGULATORY MECHANISMS SPECIFIC TO CRSWNP. RESULTS: WE IDENTIFIED 5585 DIFFERENTIAL TRANSCRIPTIONAL AND 261 DNAM RESPONSES (FDR <0.10) TO RV BETWEEN CRSWNP CASES AND CONTROLS. THESE DIFFERENTIAL RESPONSES FORMED THREE CO-EXPRESSION/CO-METHYLATION MODULES THAT WERE RELATED TO CRSWNP AND THREE THAT WERE RELATED TO RV (BONFERRONI CORRECTED P < .01). MOST (95%) OF THE DIFFERENTIALLY METHYLATED CPGS (DMCS) WERE IN MODULES RELATED TO CRSWNP, WHEREAS THE DIFFERENTIALLY EXPRESSED GENES (DEGS) WERE MORE EQUALLY DISTRIBUTED BETWEEN THE CRSWNP- AND RV-RELATED MODULES. GENES IN THE CRSWNP-RELATED MODULES WERE ENRICHED IN KNOWN CRS AND/OR VIRAL RESPONSE IMMUNE PATHWAYS. CONCLUSION: RV ACTIVATES SPECIFIC EPIGENETIC PROGRAMS AND CORRELATED TRANSCRIPTIONAL NETWORKS IN THE SINONASAL EPITHELIUM OF INDIVIDUALS WITH CRSWNP. THESE NOVEL OBSERVATIONS SUGGEST EPIGENETIC SIGNATURES SPECIFIC TO PATIENTS WITH CRSWNP MODULATE RESPONSE TO VIRAL PATHOGENS AT THE MUCOSAL ENVIRONMENTAL INTERFACE. DETERMINING HOW VIRAL RESPONSE PATHWAYS ARE INVOLVED IN EPITHELIAL INFLAMMATION IN CRSWNP COULD LEAD TO THERAPEUTIC TARGETS FOR THIS BURDENSOME AIRWAY DISORDER. 2023 10 3186 29 HBV COVALENTLY CLOSED CIRCULAR DNA MINICHROMOSOMES IN DISTINCT EPIGENETIC TRANSCRIPTIONAL STATES DIFFER IN THEIR VULNERABILITY TO DAMAGE. BACKGROUND AND AIMS: HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IS A MAJOR OBSTACLE FOR A CURE OF CHRONIC HEPATITIS B. ACCUMULATING EVIDENCE SUGGESTS THAT EPIGENETIC MODIFICATIONS REGULATE THE TRANSCRIPTIONAL ACTIVITY OF CCCDNA MINICHROMOSOMES. HOWEVER, IT REMAINS UNCLEAR HOW THE EPIGENETIC STATE OF CCCDNA AFFECTS ITS STABILITY. APPROACHES AND RESULTS: BY USING HBV INFECTION CELL MODELS AND IN VITRO AND IN VIVO RECOMBINANT CCCDNA (RCCCDNA) AND HBVCIRCLE MODELS, THE REDUCTION RATE OF HBV CCCDNA AND THE EFFICACY OF APOLIPOPROTEIN B MRNA EDITING ENZYME CATALYTIC SUBUNIT 3A (APOBEC3A)-MEDIATED AND CRISPR/CRISPR-ASSOCIATED 9 (CAS9)-MEDIATED CCCDNA TARGETING WERE COMPARED BETWEEN CCCDNAS WITH DISTINCT TRANSCRIPTIONAL ACTIVITIES. INTERFERON-ALPHA TREATMENT AND HEPATITIS B X PROTEIN (HBX) DELETION WERE APPLIED AS TWO STRATEGIES FOR CCCDNA REPRESSION. CHROMATIN IMMUNOPRECIPITATION AND MICROCOCCAL NUCLEASE ASSAYS WERE PERFORMED TO DETERMINE THE EPIGENETIC PATTERN OF CCCDNA. HBV CCCDNA LEVELS REMAINED STABLE IN NONDIVIDING HEPATOCYTES; HOWEVER, THEY WERE SIGNIFICANTLY REDUCED DURING CELL DIVISION, AND THE REDUCTION RATE WAS SIMILAR BETWEEN CCCDNAS IN TRANSCRIPTIONALLY ACTIVE AND TRANSCRIPTIONALLY REPRESSED STATES. STRIKINGLY, HBV RCCCDNA WITHOUT HBX EXPRESSION EXHIBITED A SIGNIFICANTLY LONGER PERSISTENCE IN MICE. THE CCCDNA WITH LOW TRANSCRIPTIONAL ACTIVITY EXHIBITED AN EPIGENETICALLY INACTIVE PATTERN AND WAS MORE DIFFICULT TO ACCESS BY APOBEC3A AND ENGINEERED CRISPR-CAS9. THE EPIGENETIC REGULATOR ACTIVATING CCCDNA INCREASED ITS VULNERABILITY TO APOBEC3A. CONCLUSIONS: HBV CCCDNA MINICHROMOSOMES IN DISTINCT EPIGENETIC TRANSCRIPTIONAL STATES SHOWED A SIMILAR REDUCTION RATE DURING CELL DIVISION BUT SIGNIFICANTLY DIFFERED IN THEIR ACCESSIBILITY AND VULNERABILITY TO TARGETED NUCLEASES AND ANTIVIRAL AGENTS. EPIGENETIC SENSITIZATION OF CCCDNA MAKES IT MORE SUSCEPTIBLE TO DAMAGE AND MAY POTENTIALLY CONTRIBUTE TO AN HBV CURE. 2022 11 2143 30 EPIGENETIC LANDSCAPE OF HIV-1 INFECTION IN PRIMARY HUMAN MACROPHAGE. HUMAN IMMUNODEFICIENCY VIRUS (HIV)-INFECTED MACROPHAGES ARE LONG-LIVED CELLS THAT SUSTAIN PERSISTENT VIRUS EXPRESSION, WHICH IS BOTH A BARRIER TO VIRAL ERADICATION AND CONTRIBUTOR TO NEUROLOGICAL COMPLICATIONS IN PATIENTS DESPITE ANTIRETROVIRAL THERAPY (ART). TO BETTER UNDERSTAND THE REGULATION OF HIV-1 IN MACROPHAGES, WE COMPARED HIV-INFECTED PRIMARY HUMAN MONOCYTE-DERIVED MACROPHAGES (MDM) TO ACUTELY INFECTED PRIMARY CD4 T CELLS AND JURKAT CELLS LATENTLY INFECTED WITH HIV (JLAT 8.4). HIV GENOMES IN MDM WERE ACTIVELY TRANSCRIBED DESPITE ENRICHMENT WITH HETEROCHROMATIN-ASSOCIATED H3K9ME3 ACROSS THE COMPLETE HIV GENOME IN COMBINATION WITH ELEVATED ACTIVATION MARKS OF H3K9AC AND H3K27AC AT THE LONG TERMINAL REPEAT (LTR). MACROPHAGE PATTERNS CONTRASTED WITH JLAT CELLS, WHICH SHOWED CONVENTIONAL BIVALENT H3K4ME3/H3K27ME3, AND ACUTELY INFECTED CD4 T CELLS, WHICH SHOWED AN INTERMEDIATE EPIGENOTYPE. 5'-METHYLCYTOSINE (5MC) WAS ENRICHED ACROSS THE HIV GENOME IN LATENTLY INFECTED JLAT CELLS, WHILE 5'-HYDROXYMETHYLCYTOSINE (5HMC) WAS ENRICHED IN CD4 CELLS AND MDMS. HIV INFECTION INDUCED MULTINUCLEATION OF MDMS ALONG WITH DNA DAMAGE-ASSOCIATED P53 PHOSPHORYLATION, AS WELL AS LOSS OF TET2 AND THE NUCLEAR REDISTRIBUTION OF 5-HYDOXYMETHYLATION. TAKEN TOGETHER, OUR FINDINGS SUGGEST THAT HIV INDUCES A UNIQUE MACROPHAGE NUCLEAR AND TRANSCRIPTIONAL PROFILE, AND VIRAL GENOMES ARE MAINTAINED IN A NONCANONICAL BIVALENT EPIGENETIC STATE. IMPORTANCE MACROPHAGES SERVE AS A RESERVOIR FOR LONG-TERM PERSISTENCE AND CHRONIC PRODUCTION OF HIV. WE FOUND AN ATYPICAL EPIGENETIC CONTROL OF HIV IN MACROPHAGES MARKED BY HETEROCHROMATIC H3K9ME3 DESPITE ACTIVE VIRAL TRANSCRIPTION. HIV INFECTION INDUCED CHANGES IN MACROPHAGE NUCLEAR MORPHOLOGY AND EPIGENETIC REGULATORY FACTORS. THESE FINDINGS MAY IDENTIFY NEW MECHANISMS TO CONTROL CHRONIC HIV EXPRESSION IN INFECTED MACROPHAGES. 2022 12 4239 28 METHYLATION PROFILE OF HEPATITIS B VIRUS IS NOT INFLUENCED BY INTERFERON ALPHA IN HUMAN LIVER CANCER CELLS. INTERFERON (IFN) ALPHA IS USED FOR THE TREATMENT OF CHRONIC HEPATITIS B VIRUS (HBV) INFECTION, BUT THE MOLECULAR MECHANISMS UNDERLYING ITS ANTIVIRAL EFFECT HAVE NOT BEEN FULLY ELUCIDATED. EPIGENETIC MODIFICATIONS REGULATE THE TRANSCRIPTIONAL ACTIVITY OF COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IN CELLS WITH CHRONIC HBV INFECTION. IFN?ALPHA HAS BEEN SHOWN TO MODIFY CCCDNA?BOUND HISTONES, BUT IT IS NOT KNOWN WHETHER THE ANTI?HBV EFFECT OF IFN?ALPHA INVOLVES METHYLATION OF CCCDNA. THE PRESENT STUDY AIMED TO DETERMINE WHETHER IFN?ALPHA INDUCED METHYLATION OF HBV CCCDNA IN A CELL?BASED MODEL IN WHICH HEPG2 CELLS WERE DIRECTLY INFECTED WITH WILD?TYPE HBV VIRIONS. METHYLATION STATUS OF HBV CCCDNA WAS ASSESSED USING GLOBAL DNA METHYLATION ELISA ASSAY, METHYLATION?SPECIFIC PCR AND BISULFITE SEQUENCING. IFN?ALPHA SUPPRESSED HBV DNA AND RNA TRANSCRIPTS, BUT METHYLATION PROFILES WERE SIMILAR BETWEEN THE CONTROL AND IFN?ALPHA TREATED GROUPS. CHROMATIN IMMUNOPRECIPITATION RESULTS REVEALED BINDING OF DNA METHYLTRANSFERASES (DNMT) 3A AND DNMT3B TO HBV CCCDNA AND TREATMENT WITH IFN?ALPHA SUPPRESSED THE RECRUITMENT OF DNMT3B TO CCCDNA. TAKEN TOGETHER, THESE RESULTS SUGGEST THAT IFN?ALPHA DOES NOT INDUCE METHYLATION OF HBV CCCDNA. THEREFORE, IT WAS CONCLUDED THAT METHYLATION IS UNLIKELY TO CONTRIBUTE TO THE ANTI?HBV EFFECT OF IFN?ALPHA IN HEPG2 CELLS, AND THAT ALTERNATIVE MECHANISMS NEED TO BE SOUGHT TO ENHANCE CCCDNA METHYLATION AS A NOVEL THERAPY AGAINST HBV. 2021 13 3189 28 HBX RELIEVES CHROMATIN-MEDIATED TRANSCRIPTIONAL REPRESSION OF HEPATITIS B VIRAL CCCDNA INVOLVING SETDB1 HISTONE METHYLTRANSFERASE. BACKGROUND & AIMS: MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR HBV DNA (CCCDNA) THAT SERVES AS A TEMPLATE FOR HBV TRANSCRIPTION IS RESPONSIBLE FOR THE FAILURE OF ANTIVIRAL THERAPIES. WHILE STUDIES IN CHRONIC HEPATITIS PATIENTS HAVE SHOWN THAT HIGH VIREMIA CORRELATES WITH HYPERACETYLATION OF CCCDNA-ASSOCIATED HISTONES, THE MOLECULAR MECHANISMS CONTROLLING CCCDNA STABILITY AND TRANSCRIPTIONAL REGULATION ARE STILL POORLY UNDERSTOOD. THIS STUDY AIMED TO DECIPHER THE ROLE OF CHROMATIN AND CHROMATIN MODIFIER PROTEINS ON HBV TRANSCRIPTION. METHODS: WE ANALYZED THE CHROMATIN STRUCTURE OF ACTIVELY TRANSCRIBED OR SILENCED CCCDNA BY INFECTING PRIMARY HUMAN HEPATOCYTES AND DIFFERENTIATED HEPARG CELLS WITH WILD-TYPE VIRUS OR VIRUS DEFICIENT (HBVX-) FOR THE EXPRESSION OF HEPATITIS B VIRUS X PROTEIN (HBX), THAT IS REQUIRED FOR HBV EXPRESSION. RESULTS: IN THE ABSENCE OF HBX, HBV CCCDNA WAS TRANSCRIPTIONALLY SILENCED WITH THE CONCOMITANT DECREASE OF HISTONE 3 (H3) ACETYLATION AND H3K4ME3, INCREASE OF H3 DI- AND TRI-METHYLATION (H3K9ME) AND THE RECRUITMENT OF HETEROCHROMATIN PROTEIN 1 FACTORS (HP1) THAT CORRELATE WITH CONDENSED CHROMATIN. SETDB1 WAS FOUND TO BE THE MAIN HISTONE METHYLTRANSFERASE RESPONSIBLE FOR THE DEPOSITION OF H3K9ME3 AND HBV REPRESSION. FINALLY, FULL TRANSCRIPTIONAL REACTIVATION OF HBVX- UPON HBX RE-EXPRESSION CORRELATED WITH AN INCREASE OF HISTONE ACETYLATION AND H3K4ME3, AND A CONCOMITANT DECREASE OF HP1 BINDING AND OF H3K9ME3 ON THE CCCDNA. CONCLUSION: UPON HBV INFECTION, CELLULAR MECHANISMS INVOLVING SETDB1-MEDIATED H3K9ME3 AND HP1 INDUCE SILENCING OF HBV CCCDNA TRANSCRIPTION THROUGH MODULATION OF CHROMATIN STRUCTURE. HBX IS ABLE TO RELIEVE THIS REPRESSION AND ALLOW THE ESTABLISHMENT OF ACTIVE CHROMATIN. 2015 14 3340 26 HISTONE DEACETYLASE MEDIATED TRANSCRIPTIONAL ACTIVATION REDUCES PROVIRAL LOADS IN HTLV-1 ASSOCIATED MYELOPATHY/TROPICAL SPASTIC PARAPARESIS PATIENTS. EPIGENETIC MODIFICATIONS OF CHROMATIN MAY PLAY A ROLE IN MAINTAINING VIRAL LATENCY AND THUS PERSISTENCE OF THE HUMAN T-LYMPHOTROPIC VIRUS TYPE 1 (HTLV-1), WHICH IS RESPONSIBLE FOR HTLV-ASSOCIATED MYELOPATHY/TROPICAL SPASTIC PARAPARESIS (HAM/TSP). A MAJOR DETERMINANT OF DISEASE PROGRESSION IS INCREASED PERIPHERAL BLOOD PROVIRAL LOAD (PVL), POSSIBLY VIA THE ACCUMULATION OF INFECTED CELLS IN THE CENTRAL NERVOUS SYSTEM (CNS) CREATING A DAMAGING INFLAMMATORY RESPONSE. CURRENT THERAPEUTIC APPROACHES THAT FOCUS ON REDUCING EITHER CELL PROLIFERATION, VIRAL REPLICATION, OR TISSUE INVASION ARE STILL UNSATISFACTORY. CONTRASTING WITH THESE INHIBITORY STRATEGIES, WE EVALUATED THE EFFICACY OF A NOVEL APPROACH AIMED, PARADOXICALLY, AT ACTIVATING VIRAL GENE EXPRESSION TO EXPOSE VIRUS-POSITIVE CELLS TO THE HOST IMMUNE RESPONSE. WE USED VALPROATE (VPA), A HISTONE DEACETYLASE INHIBITOR THAT HAS BEEN USED FOR DECADES AS A CHRONIC, SAFE TREATMENT FOR EPILEPTIC DISORDERS. BASED ON IN VITRO AND IN VIVO DATA, WE PROVIDE EVIDENCE THAT TRANSIENT ACTIVATION OF THE LATENT VIRAL RESERVOIR CAUSES ITS COLLAPSE, A PROCESS THAT MAY ALLEVIATE THE CONDITION OF HAM/TSP. THIS REPRESENTS THE FIRST SUCH APPROACH TO TREATING HAM/TSP, USING GENE ACTIVATION THERAPY TO TILT THE HOST-PATHOGEN BALANCE IN FAVOR OF AN EXISTING ANTIVIRAL RESPONSE. THIS TRIAL IS REGISTERED AT HTTP://CLINICALTRIALS.GOV/AS NO. NCT00519181. 2007 15 938 31 CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) RISK IS MEDIATED BY MULTIPLE ENHANCER VARIANTS WITHIN CLL RISK LOCI. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON ADULT LEUKEMIA IN WESTERN COUNTRIES. IT HAS A STRONG GENETIC BASIS, SHOWING A ~ 8-FOLD INCREASED RISK OF CLL IN FIRST-DEGREE RELATIVES. GENOME-WIDE ASSOCIATION STUDIES (GWAS) HAVE IDENTIFIED 41 RISK VARIANTS ACROSS 41 LOCI. HOWEVER, FOR A MAJORITY OF THE LOCI, THE FUNCTIONAL VARIANTS AND THE MECHANISMS UNDERLYING THEIR CAUSAL ROLES REMAIN UNDEFINED. HERE, WE EXAMINED THE GENETIC AND EPIGENETIC FEATURES ASSOCIATED WITH 12 INDEX VARIANTS, ALONG WITH ANY CORRELATED (R2 >/= 0.5) VARIANTS, AT THE CLL RISK LOCI LOCATED OUTSIDE OF GENE PROMOTERS. BASED ON PUBLICLY AVAILABLE CHIP-SEQ AND CHROMATIN ACCESSIBILITY DATA AS WELL AS OUR OWN CHIP-SEQ DATA FROM CLL PATIENTS, WE IDENTIFIED SIX CANDIDATE FUNCTIONAL VARIANTS AT SIX LOCI AND AT LEAST TWO CANDIDATE FUNCTIONAL VARIANTS AT EACH OF THE REMAINING SIX LOCI. THE FUNCTIONAL VARIANTS ARE PREDOMINANTLY LOCATED WITHIN ENHANCERS OR SUPER-ENHANCERS, INCLUDING BI-DIRECTIONALLY TRANSCRIBED ENHANCERS, WHICH ARE OFTEN RESTRICTED TO IMMUNE CELL TYPES. FURTHERMORE, WE FOUND THAT, AT 78% OF THE FUNCTIONAL VARIANTS, THE ALTERNATIVE ALLELES ALTERED THE TRANSCRIPTION FACTOR BINDING MOTIFS OR HISTONE MODIFICATIONS, INDICATING THE INVOLVEMENT OF THESE VARIANTS IN THE CHANGE OF LOCAL CHROMATIN STATE. FINALLY, THE ENHANCERS CARRYING FUNCTIONAL VARIANTS PHYSICALLY INTERACTED WITH GENES ENRICHED IN THE TYPE I INTERFERON SIGNALING PATHWAY, APOPTOSIS, OR TP53 NETWORK THAT ARE KNOWN TO PLAY KEY ROLES IN CLL. THESE RESULTS SUPPORT THE REGULATORY ROLES FOR INHERITED NONCODING VARIANTS IN THE PATHOGENESIS OF CLL. 2020 16 5226 32 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 17 6542 37 TRANSCRIPTOME ARCHITECTURE OF OSTEOBLASTIC CELLS INFECTED WITH STAPHYLOCOCCUS AUREUS REVEALS STRONG INFLAMMATORY RESPONSES AND SIGNATURES OF METABOLIC AND EPIGENETIC DYSREGULATION. STAPHYLOCOCCUS AUREUS IS AN OPPORTUNISTIC PATHOGEN THAT CAUSES A RANGE OF DEVASTATING DISEASES INCLUDING CHRONIC OSTEOMYELITIS, WHICH PARTIALLY RELIES ON THE INTERNALIZATION AND PERSISTENCE OF S. AUREUS IN OSTEOBLASTS. THE IDENTIFICATION OF THE MECHANISMS OF THE OSTEOBLAST RESPONSE TO INTRACELLULAR S. AUREUS IS THUS CRUCIAL TO IMPROVE THE KNOWLEDGE OF THIS INFECTIOUS PATHOLOGY. SINCE THE SIGNAL FROM SPECIFICALLY INFECTED BACTERIA-BEARING CELLS IS DILUTED AND THE RESULTS ARE CONFOUNDED BY BYSTANDER EFFECTS OF UNINFECTED CELLS, WE DEVELOPED A NOVEL MODEL OF LONG-TERM INFECTION. USING A FLOW CYTOMETRIC APPROACH WE ISOLATED ONLY S. AUREUS-BEARING CELLS FROM MIXED POPULATIONS THAT ALLOWS TO IDENTIFY SIGNALS SPECIFIC TO INTRACELLULAR INFECTION. HERE WE PRESENT AN IN-DEPTH ANALYSIS OF THE EFFECT OF LONG-TERM S. AUREUS INFECTION ON THE TRANSCRIPTIONAL PROGRAM OF HUMAN OSTEOBLAST-LIKE CELLS. AFTER RNA-SEQ AND KEGG AND REACTOME PATHWAY ENRICHMENT ANALYSIS, THE REMODELED TRANSCRIPTOMIC PROFILE OF INFECTED CELLS REVEALED EXACERBATED IMMUNE AND INFLAMMATORY RESPONSES, AS WELL AS METABOLIC DYSREGULATIONS THAT LIKELY INFLUENCE THE INTRACELLULAR LIFE OF BACTERIA. NUMEROUS GENES ENCODING EPIGENETIC REGULATORS WERE DOWNREGULATED. THE LATER INCLUDED GENES CODING FOR COMPONENTS OF CHROMATIN-REPRESSIVE COMPLEXES (E.G., NURD, BAHD1 AND PRC1) AND EPIFACTORS INVOLVED IN DNA METHYLATION. SETS OF GENES ENCODING PROTEINS OF CELL ADHESION OR NEUROTRANSMISSION WERE ALSO DEREGULATED. OUR RESULTS SUGGEST THAT INTRACELLULAR S. AUREUS INFECTION HAS A LONG-TERM IMPACT ON THE GENOME AND EPIGENOME OF HOST CELLS, WHICH MAY EXERT PATHO-PHYSIOLOGICAL DYSFUNCTIONS ADDITIONALLY TO THE DEFENSE RESPONSE DURING THE INFECTION PROCESS. OVERALL, THESE RESULTS NOT ONLY IMPROVE OUR CONCEPTUAL UNDERSTANDING OF BIOLOGICAL PROCESSES INVOLVED IN THE LONG-TERM S. AUREUS INFECTIONS OF OSTEOBLAST-LIKE CELLS, BUT ALSO PROVIDE AN ATLAS OF DEREGULATED HOST GENES AND BIOLOGICAL PATHWAYS AND IDENTIFY NOVEL MARKERS AND POTENTIAL CANDIDATES FOR PROPHYLACTIC AND THERAPEUTIC APPROACHES. 2022 18 5689 23 SILENCING HEPATITIS B VIRUS COVALENTLY CLOSED CIRCULAR DNA: THE POTENTIAL OF AN EPIGENETIC THERAPY APPROACH. GLOBAL PROPHYLACTIC VACCINATION PROGRAMMES HAVE HELPED TO CURB NEW HEPATITIS B VIRUS (HBV) INFECTIONS. HOWEVER, IT IS ESTIMATED THAT NEARLY 300 MILLION PEOPLE ARE CHRONICALLY INFECTED AND HAVE A HIGH RISK OF DEVELOPING HEPATOCELLULAR CARCINOMA. AS SUCH, HBV REMAINS A SERIOUS HEALTH PRIORITY AND THE DEVELOPMENT OF NOVEL CURATIVE THERAPEUTICS IS URGENTLY NEEDED. CHRONIC HBV INFECTION HAS BEEN ATTRIBUTED TO THE PERSISTENCE OF THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) WHICH ESTABLISHES ITSELF AS A MINICHROMOSOME IN THE NUCLEUS OF HEPATOCYTES. AS THE VIRAL TRANSCRIPTION INTERMEDIATE, THE CCCDNA IS RESPONSIBLE FOR PRODUCING NEW VIRIONS AND PERPETUATING INFECTION. HBV IS DEPENDENT ON VARIOUS HOST FACTORS FOR CCCDNA FORMATION AND THE MINICHROMOSOME IS AMENABLE TO EPIGENETIC MODIFICATIONS. TWO HBV PROTEINS, X (HBX) AND CORE (HBC) PROMOTE VIRAL REPLICATION BY MODULATING THE CCCDNA EPIGENOME AND REGULATING HOST CELL RESPONSES. THIS INCLUDES VIRAL AND HOST GENE EXPRESSION, CHROMATIN REMODELING, DNA METHYLATION, THE ANTIVIRAL IMMUNE RESPONSE, APOPTOSIS, AND UBIQUITINATION. ELIMINATION OF THE CCCDNA MINICHROMOSOME WOULD RESULT IN A STERILIZING CURE; HOWEVER, THIS MAY BE DIFFICULT TO ACHIEVE. EPIGENETIC THERAPIES COULD PERMANENTLY SILENCE THE CCCDNA MINICHROMOSOME AND PROMOTE A FUNCTIONAL CURE. THIS REVIEW EXPLORES THE CCCDNA EPIGENOME, HOW HOST AND VIRAL FACTORS INFLUENCE TRANSCRIPTION, AND THE RECENT EPIGENETIC THERAPIES AND EPIGENOME ENGINEERING APPROACHES THAT HAVE BEEN DESCRIBED. 2021 19 5368 23 RECENT ADVANCES IN THE STUDY OF HEPATITIS B VIRUS COVALENTLY CLOSED CIRCULAR DNA. CHRONIC HEPATITIS B INFECTION IS CAUSED BY HEPATITIS B VIRUS (HBV) AND A TOTAL CURE IS YET TO BE ACHIEVED. THE VIRAL COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IS THE KEY TO ESTABLISH A PERSISTENT INFECTION WITHIN HEPATOCYTES. CURRENT ANTIVIRAL STRATEGIES HAVE NO EFFECT ON THE PRE-EXISTING CCCDNA RESERVOIR. THEREFORE, THE STUDY OF THE MOLECULAR MECHANISM OF CCCDNA FORMATION IS BECOMING A MAJOR FOCUS OF HBV RESEARCH. THIS REVIEW SUMMARIZES THE CURRENT ADVANCES IN CCCDNA MOLECULAR BIOLOGY AND THE LATEST STUDIES ON THE ELIMINATION OR INACTIVATION OF CCCDNA, INCLUDING THREE MAJOR AREAS: (1) EPIGENETIC REGULATION OF CCCDNA BY HBV X PROTEIN, (2) IMMUNE-MEDIATED DEGRADATION, AND (3) GENOME-EDITING NUCLEASES. ALL THESE ASPECTS PROVIDE CLUES ON HOW TO FINALLY ATTAIN A CURE FOR CHRONIC HEPATITIS B INFECTION. 2017 20 304 46 AIRWAY AGING AND METHYLATION DISRUPTIONS IN HIV-ASSOCIATED CHRONIC OBSTRUCTIVE PULMONARY DISEASE. RATIONALE: AGE-RELATED DISEASES LIKE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) OCCUR AT HIGHER RATES IN PEOPLE LIVING WITH HUMAN IMMUNODEFICIENCY VIRUS (PLWH) THAN IN UNINFECTED POPULATIONS. OBJECTIVES: TO IDENTIFY WHETHER ACCELERATED AGING CAN BE OBSERVED IN THE AIRWAYS OF PLWH WITH COPD, MANIFEST BY A UNIQUE DNA METHYLATION SIGNATURE. METHODS: BRONCHIAL EPITHELIAL BRUSHINGS FROM PLWH WITH AND WITHOUT COPD AND HIV-UNINFECTED ADULTS WITH AND WITHOUT COPD (N = 76) WERE PROFILED FOR DNA METHYLATION AND GENE EXPRESSION. WE EVALUATED GLOBAL ALU AND LINE-1 METHYLATION AND CALCULATED THE EPIGENETIC AGE USING THE HORVATH CLOCK AND THE METHYLATION TELOMERE LENGTH ESTIMATOR. TO IDENTIFY GENOME-WIDE DIFFERENTIAL DNA METHYLATION AND GENE EXPRESSION ASSOCIATED WITH HIV AND COPD, ROBUST LINEAR MODELS WERE USED FOLLOWED BY AN EXPRESSION QUANTITATIVE TRAIT METHYLATION (EQTM) ANALYSIS. MEASUREMENTS AND MAIN RESULTS: EPIGENETIC AGE ACCELERATION AND SHORTER METHYLATION ESTIMATES OF TELOMERE LENGTH WERE FOUND IN PLWH WITH COPD COMPARED WITH PLWH WITHOUT COPD AND UNINFECTED PATIENTS WITH AND WITHOUT COPD. GLOBAL HYPOMETHYLATION WAS IDENTIFIED IN PLWH. WE IDENTIFIED 7,970 CYTOSINE BASES LOCATED NEXT TO A GUANINE BASE (CPG SITES), 293 GENES, AND 9 EXPRESSION QUANTITATIVE TRAIT METHYLATION-GENE PAIRS ASSOCIATED WITH THE INTERACTION BETWEEN HIV AND COPD. ACTIN BINDING LIM PROTEIN FAMILY MEMBER 3 (ABLIM3) WAS ONE OF THE NOVEL CANDIDATE GENES FOR HIV-ASSOCIATED COPD HIGHLIGHTED BY OUR ANALYSIS. CONCLUSIONS: METHYLATION AGE ACCELERATION IS OBSERVED IN THE AIRWAY EPITHELIUM OF PLWH WITH COPD, A PROCESS THAT MAY BE RESPONSIBLE FOR THE HEIGHTENED RISK OF COPD IN THIS POPULATION. THEIR DISTINCT METHYLATION PROFILE, DIFFERING FROM THAT OBSERVED IN PATIENTS WITH COPD ALONE, SUGGESTS A UNIQUE PATHOGENESIS TO HIV-ASSOCIATED COPD. THE ASSOCIATIONS WARRANT FURTHER INVESTIGATION TO ESTABLISH CAUSALITY. 2022