1 4563 134 MYELOID DNA METHYLTRANSFERASE3B DEFICIENCY AGGRAVATES PULMONARY FIBROSIS BY ENHANCING PROFIBROTIC MACROPHAGE ACTIVATION. BACKGROUND: IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE AND SEVERE DISEASE CHARACTERIZED BY EXCESSIVE MATRIX DEPOSITION IN THE LUNGS. MACROPHAGES PLAY CRUCIAL ROLES IN MAINTAINING LUNG HOMEOSTASIS BUT ARE ALSO CENTRAL IN THE PATHOGENESIS OF LUNG DISEASES LIKE PULMONARY FIBROSIS. ESPECIALLY, MACROPHAGE POLARIZATION/ACTIVATION SEEMS TO PLAY A CRUCIAL ROLE IN PATHOLOGY AND EPIGENETIC REPROGRAMING IS WELL-KNOWN TO REGULATE MACROPHAGE POLARIZATION. DNA METHYLATION ALTERATIONS IN IPF LUNGS HAVE BEEN WELL DOCUMENTED, BUT THE ROLE OF DNA METHYLATION IN SPECIFIC CELL TYPES, ESPECIALLY MACROPHAGES, IS POORLY DEFINED. METHODS: IN ORDER TO DETERMINE THE ROLE OF DNA METHYLATION IN MACROPHAGES DURING PULMONARY FIBROSIS, WE SUBJECTED MACROPHAGE SPECIFIC DNA METHYLTRANSFERASE (DNMT)3B, WHICH MEDIATES THE DE NOVO DNA METHYLATION, DEFICIENT MICE TO THE BLEOMYCIN-INDUCED PULMONARY FIBROSIS MODEL. MACROPHAGE POLARIZATION AND FIBROTIC PARAMETERS WERE EVALUATED AT 21 DAYS AFTER BLEOMYCIN ADMINISTRATION. DNMT3B KNOCKOUT AND WILD TYPE BONE MARROW-DERIVED MACROPHAGES WERE STIMULATED WITH EITHER INTERLEUKIN (IL)4 OR TRANSFORMING GROWTH FACTOR BETA 1 (TGFB1) IN VITRO, AFTER WHICH PROFIBROTIC GENE EXPRESSION AND DNA METHYLATION AT THE ARG1 PROMOTOR WERE DETERMINED. RESULTS: WE SHOW THAT DNMT3B DEFICIENCY PROMOTES ALTERNATIVE MACROPHAGE POLARIZATION INDUCED BY IL4 AND TGFB1 IN VITRO AND ALSO ENHANCES PROFIBROTIC MACROPHAGE POLARIZATION IN THE ALVEOLAR SPACE DURING PULMONARY FIBROSIS IN VIVO. MOREOVER, MYELOID SPECIFIC DELETION OF DNMT3B PROMOTED THE DEVELOPMENT OF EXPERIMENTAL PULMONARY FIBROSIS. CONCLUSIONS: IN SUMMARY, THESE DATA SUGGEST THAT MYELOID DNMT3B REPRESSES FIBROTIC MACROPHAGE POLARIZATION AND PROTECTS AGAINST BLEOMYCIN INDUCED PULMONARY FIBROSIS. 2022 2 1709 30 DYSFUNCTIONAL ERG SIGNALING DRIVES PULMONARY VASCULAR AGING AND PERSISTENT FIBROSIS. VASCULAR DYSFUNCTION IS A HALLMARK OF CHRONIC DISEASES IN ELDERLY. THE CONTRIBUTION OF THE VASCULATURE TO LUNG REPAIR AND FIBROSIS IS NOT FULLY UNDERSTOOD. HERE, WE PERFORMED AN EPIGENETIC AND TRANSCRIPTIONAL ANALYSIS OF LUNG ENDOTHELIAL CELLS (ECS) FROM YOUNG AND AGED MICE DURING THE RESOLUTION OR PROGRESSION OF BLEOMYCIN-INDUCED LUNG FIBROSIS. WE IDENTIFIED THE TRANSCRIPTION FACTOR ETS-RELATED GENE (ERG) AS PUTATIVE ORCHESTRATOR OF LUNG CAPILLARY HOMEOSTASIS AND REPAIR, AND WHOSE FUNCTION IS DYSREGULATED IN AGING. ERG DYSREGULATION IS ASSOCIATED WITH REDUCED CHROMATIN ACCESSIBILITY AND MALADAPTIVE TRANSCRIPTIONAL RESPONSES TO INJURY. LOSS OF ENDOTHELIAL ERG ENHANCES PARACRINE FIBROBLAST ACTIVATION IN VITRO, AND IMPAIRS LUNG FIBROSIS RESOLUTION IN YOUNG MICE IN VIVO. SCRNA-SEQ OF ERG DEFICIENT MOUSE LUNGS REVEALES TRANSCRIPTIONAL AND FIBROGENIC ABNORMALITIES RESEMBLING THOSE ASSOCIATED WITH AGING AND HUMAN LUNG FIBROSIS, INCLUDING REDUCED NUMBER OF GENERAL CAPILLARY (GCAP) ECS. OUR FINDINGS DEMONSTRATE THAT LUNG ENDOTHELIAL CHROMATIN REMODELING DETERIORATES WITH AGING LEADING TO ABNORMAL TRANSCRIPTION, VASCULAR DYSREPAIR, AND PERSISTENT FIBROSIS FOLLOWING INJURY. 2022 3 5054 35 PHARMACOPROTEOMICS REVEAL NOVEL PROTECTIVE ACTIVITY OF BROMODOMAIN CONTAINING 4 INHIBITORS ON VASCULAR HOMEOSTASIS IN TLR3-MEDIATED AIRWAY REMODELING. SMALL MOLECULE INHIBITORS OF THE EPIGENETIC REGULATOR BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) ARE POTENTIAL THERAPEUTICS FOR VIRAL AND ALLERGEN-INDUCED AIRWAY REMODELING. A LIMITATION OF THEIR PRECLINICAL ADVANCEMENT IS THE LACK OF DETAILED UNDERSTANDING OF MECHANISMS OF ACTION AND BIOMARKERS OF EFFECT. WE REPORT A SYSTEMS-LEVEL PHARMACOPROTEOMICS IN A STANDARDIZED MURINE MODEL OF TOLL-LIKE RECEPTOR TLR3-NFKAPPAB/RELA INNATE INFLAMMATION IN THE ABSENCE OR PRESENCE OF A HIGHLY SELECTIVE BRD4 INHIBITOR (ZL0454) OR NONSELECTIVE BROMODOMAIN AND EXTRATERMINAL DOMAIN INHIBITOR (JQ1). PROTEOMICS OF BRONCHOALVEOLAR LAVAGE FLUID (BALF) SECRETOME AND EXOSOMAL PROTEINS FROM THIS MURINE MODEL REVEALED INCREASED, SELECTIVE, CAPILLARY LEAK ASSOCIATED WITH PERICYTE-MYOFIBROBLAST TRANSITION, A PHENOMENON BLOCKED BY BRD4 INHIBITORS. BALF PROTEOMICS ALSO SUGGESTED THAT ZL0454 BETTER REDUCED THE VASCULAR LEAKAGE AND EXTRACELLULAR MATRIX DEPOSITION THAN JQ1. A SIGNIFICANT SUBSET OF INFLAMMATION-MEDIATED REMODELING FACTORS WAS ALSO IDENTIFIED IN A MOUSE MODEL OF IDIOPATHIC PULMONARY FIBROSIS PRODUCED BY BLEOMYCIN. BALF EXOSOME ANALYSIS INDICATED THAT BRD4 INHIBITORS REDUCED THE INDUCTION OF EXOSOMES ENRICHED IN COAGULATION FACTORS WHOSE PRESENCE CORRELATED WITH INTERSTITIAL FIBRIN DEPOSITION. FINALLY, BALF SAMPLES FROM HUMANS WITH SEVERE ASTHMA DEMONSTRATED SIMILAR UPREGULATIONS OF ORM2, APCS, SPARCL1, FGA, AND FN1, SUGGESTING THEIR POTENTIAL AS BIOMARKERS FOR EARLY DETECTION OF AIRWAY REMODELING AND/OR MONITORING OF THERAPY RESPONSE. SIGNIFICANCE: REPETITIVE AND CHRONIC VIRAL UPPER RESPIRATORY TRACT INFECTIONS TRIGGER TOLL-LIKE RECEPTOR (TLR)3-NFKAPPAB/RELA MEDIATED AIRWAY REMODELING WHICH IS LINKED TO A PROGRESSIVE DECLINE IN PULMONARY FUNCTION IN PATIENTS WITH ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. SMALL MOLECULE INHIBITORS OF THE EPIGENETIC REGULATOR BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) ARE POTENTIAL THERAPEUTICS FOR VIRAL AND ALLERGEN-INDUCED AIRWAY REMODELING. A LIMITATION OF THEIR PRECLINICAL ADVANCEMENT IS THE LACK OF DETAILED UNDERSTANDING OF MECHANISMS OF ACTION AND BIOMARKERS OF EFFECT. OUR STUDY REVEALED THAT THE ACTIVATION OF (TLR)3-NFKAPPAB/RELA PATHWAY IN THE LUNG INDUCED AN ELEVATION IN COAGULATION, COMPLEMENT, AND PLATELET FACTORS, INDICATING THE INCREASED VASCULAR LEAK DURING AIRWAY REMODELING. THE MECHANISM OF VASCULAR LEAKAGE WAS CHRONIC INFLAMMATION-INDUCED PERICYTE-MYOFIBROBLAST TRANSITION, WHICH WAS BLOCKED BY BRD4 INHIBITORS. FINALLY, PROTEOMICS ANALYSIS OF THE BRONCHOALVEOLAR LAVAGE FLUID SAMPLES FROM HUMANS WITH SEVERE ASTHMA DEMONSTRATED SIMILAR FINDINGS THAT WE OBSERVED IN THE ANIMAL MODEL. 2019 4 3628 34 INACTIVATION OF NUCLEAR HISTONE DEACETYLASES BY EP300 DISRUPTS THE MICEE COMPLEX IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE, AND HIGHLY LETHAL LUNG DISEASE WITH UNKNOWN ETIOLOGY AND POOR PROGNOSIS. IPF PATIENTS DIE WITHIN 2 YEARS AFTER DIAGNOSIS MOSTLY DUE TO RESPIRATORY FAILURE. CURRENT TREATMENTS AGAINST IPF AIM TO AMELIORATE PATIENT SYMPTOMS AND TO DELAY DISEASE PROGRESSION. UNFORTUNATELY, THERAPIES TARGETING THE CAUSES OF OR REVERTING IPF HAVE NOT YET BEEN DEVELOPED. HERE WE SHOW THAT REDUCED LEVELS OF MIRNA LETHAL 7D (MIRLET7D) IN IPF COMPROMISE EPIGENETIC GENE SILENCING MEDIATED BY THE RIBONUCLEOPROTEIN COMPLEX MICEE. IN ADDITION, WE FIND THAT HYPERACTIVE EP300 REDUCES NUCLEAR HDAC ACTIVITY AND INTERFERES WITH MICEE FUNCTION IN IPF. REMARKABLY, EP300 INHIBITION REDUCES FIBROTIC HALLMARKS OF IN VITRO (PATIENT-DERIVED PRIMARY FIBROBLAST), IN VIVO (BLEOMYCIN MOUSE MODEL), AND EX VIVO (PRECISION-CUT LUNG SLICES, PCLS) IPF MODELS. OUR WORK PROVIDES THE MOLECULAR BASIS FOR THERAPIES AGAINST IPF USING EP300 INHIBITION. 2019 5 5227 33 PRMT6 MEDIATES INFLAMMATION VIA ACTIVATION OF THE NF-KAPPAB/P65 PATHWAY ON A CIGARETTE SMOKE EXTRACT-INDUCED MURINE EMPHYSEMA MODEL. INTRODUCTION: SMOKE-DRIVEN LUNG INFLAMMATION IS CONSIDERED TO BE THE MAJOR PATHOPHYSIOLOGY MECHANISM OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)/EMPHYSEMA. PROTEIN ARGININE METHYLTRANSFERASE 6 (PRMT6) IS A KEY EPIGENETIC ENZYME, WHICH IS RELATED TO PROTECTING THE TRI-METHYLATION OF H3K4 (H3K4ME3). WE HYPOTHESIZED THAT PTMT6 PROTECTS LUNG INFLAMMATION THROUGH THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY. METHODS: MICE WERE INJECTED WITH CIGARETTE SMOKE EXTRACT (CSE) OR PBS TO ESTABLISH A MICE MODEL, INTRATRACHEALLY INSTILLED WITH OVEREXPRESSED PRMT6 OR NEGATIVE CONTROL VECTOR. MORPHOMETRY OF LUNG SLIDES AND LUNG FUNCTION WERE MEASURED. WE DETERMINED THE PROTEIN EXPRESSION OF PRMT6 AND ITS RELATED HISTONE TARGETS, THE ACTIVATION OF NF-KAPPAB PATHWAY, THE LEVEL OF TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) AND INTERLEUKIN-1BETA (IL-1BETA). RESULTS: AFTER PRMT6 OVEREXPRESSION, THE MORPHOMETRY INDEXES AND LUNG FUNCTION WERE IMPROVED. ALSO, THE EXPRESSION OF H3K4ME3 WAS DECREASED. OVEREXPRESSED PRMT6 COULD SUPPRESS CSE-INDUCED NF-KAPPAB ACTIVATION AND PRO-INFLAMMATION GENES EXPRESSION. CONCLUSIONS: THE OVEREXPRESSED PRMT6 COULD SERVE AS AN INFLAMMATION INHIBITOR, POTENTIALLY THROUGH BLOCKING THE NF-KAPPAB/P65 PATHWAY IN THE MURINE EMPHYSEMA MODEL. 2020 6 692 33 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 7 6546 35 TRANSCRIPTOMIC AND EPIGENETIC PROFILING OF FIBROBLASTS IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF), A DEVASTATING, FIBROPROLIFERATIVE, CHRONIC LUNG DISORDER, IS ASSOCIATED WITH EXPANSION OF FIBROBLASTS/MYOFIBROBLASTS, WHICH LEADS TO EXCESSIVE PRODUCTION AND DEPOSITION OF EXTRACELLULAR MATRIX. IPF IS TYPICALLY CLINICALLY IDENTIFIED AS END-STAGE LUNG DISEASE, AFTER FIBROTIC PROCESSES ARE WELL-ESTABLISHED AND ADVANCED. FIBROBLASTS HAVE BEEN SHOWN TO BE CRITICALLY IMPORTANT IN THE DEVELOPMENT AND PROGRESSION OF IPF. WE HYPOTHESIZE THAT DIFFERENTIAL CHROMATIN ACCESS CAN DRIVE GENETIC DIFFERENCES IN IPF FIBROBLASTS RELATIVE TO HEALTHY FIBROBLASTS. TO THIS END, WE PERFORMED ASSAY OF TRANSPOSASE-ACCESSIBLE CHROMATIN SEQUENCING TO IDENTIFY DIFFERENTIALLY ACCESSIBLE REGIONS WITHIN THE GENOMES OF FIBROBLASTS FROM HEALTHY AND IPF LUNGS. MULTIPLE MOTIFS WERE IDENTIFIED TO BE ENRICHED IN IPF FIBROBLASTS COMPARED WITH HEALTHY FIBROBLASTS, INCLUDING BINDING MOTIFS FOR TWIST1 AND FOXA1. RNA SEQUENCING IDENTIFIED 93 GENES THAT COULD BE ANNOTATED TO DIFFERENTIALLY ACCESSIBLE REGIONS. PATHWAY ANALYSIS OF THE ANNOTATED GENES IDENTIFIED CELLULAR ADHESION, CYTOSKELETAL ANCHORING, AND CELL DIFFERENTIATION AS IMPORTANT BIOLOGICAL PROCESSES. IN ADDITION, SINGLE NUCLEOTIDE POLYMORPHISM ANALYSIS SHOWED THAT LINKAGE DISEQUILIBRIUM BLOCKS OF IPF RISK SINGLE NUCLEOTIDE POLYMORPHISMS WITH IPF-ACCESSIBLE REGIONS THAT HAVE BEEN IDENTIFIED TO BE LOCATED IN GENES THAT ARE IMPORTANT IN IPF, INCLUDING MUC5B, TERT, AND TOLLIP. VALIDATION STUDIES IN ISOLATED LUNG TISSUE CONFIRMED INCREASED EXPRESSION FOR TWIST1 AND FOXA1 IN ADDITION TO REVEALING SHANK2 AND CSPR2 AS NOVEL TARGETS. THUS, MODULATION OF DIFFERENTIAL CHROMATIN ACCESS MAY BE AN IMPORTANT MECHANISM IN THE PATHOGENESIS OF LUNG FIBROSIS. 2022 8 3924 36 LIPOSOMAL UHRF1 SIRNA SHOWS LUNG FIBROSIS TREATMENT POTENTIAL THROUGH REGULATION OF FIBROBLAST ACTIVATION. PULMONARY FIBROSIS IS A CHRONIC AND PROGRESSIVE INTERSTITIAL LUNG DISEASE ASSOCIATED WITH THE DECAY OF PULMONARY FUNCTION, WHICH LEADS TO A FATAL OUTCOME. AS AN ESSENTIAL EPIGENETIC REGULATOR OF DNA METHYLATION, THE INVOLVEMENT OF UBIQUITIN-LIKE CONTAINING PHD AND RING FINGER DOMAINS 1 (UHRF1) IN FIBROBLAST ACTIVATION REMAINS LARGELY UNDEFINED IN PULMONARY FIBROSIS. IN THE PRESENT STUDY, WE FOUND THAT TGF-BETA1-MEDIATED UPREGULATION OF UHRF1 REPRESSED BECLIN 1 VIA METHYLATED INDUCTION OF ITS PROMOTER, WHICH FINALLY RESULTED IN FIBROBLAST ACTIVATION AND LUNG FIBROSIS BOTH IN VITRO AND IN VIVO. MOREOVER, KNOCKDOWN OF UHRF1 SIGNIFICANTLY ARRESTED FIBROBLAST PROLIFERATION AND REACTIVATED BECLIN 1 IN LUNG FIBROBLASTS. THUS, INTRAVENOUS ADMINISTRATION OF UHRF1 SIRNA-LOADED LIPOSOMES SIGNIFICANTLY PROTECTED MICE AGAINST EXPERIMENTAL PULMONARY FIBROSIS. ACCORDINGLY, OUR DATA SUGGEST THAT UHRF1 MIGHT BE A NOVEL POTENTIAL THERAPEUTIC TARGET IN THE PATHOGENESIS OF PULMONARY FIBROSIS. 2022 9 699 37 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 10 698 38 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 11 137 36 ABERRANT DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 IN AIRWAY EPITHELIUM OF PATIENTS WITH COPD. BACKGROUND: GOBLET CELL METAPLASIA, A COMMON FEATURE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IS ASSOCIATED WITH MUCUS HYPERSECRETION WHICH CONTRIBUTES TO THE MORBIDITY AND MORTALITY AMONG PATIENTS. TRANSCRIPTION FACTORS SAM-POINTED DOMAIN-CONTAINING ETS-LIKE FACTOR (SPDEF) AND FORKHEAD BOX PROTEIN A2 (FOXA2) REGULATE GOBLET CELL DIFFERENTIATION. THIS STUDY AIMED TO (1) INVESTIGATE DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 DURING GOBLET CELL DIFFERENTIATION AND (2) COMPARE THIS IN AIRWAY EPITHELIAL CELLS FROM PATIENTS WITH COPD AND CONTROLS DURING MUCOCILIARY DIFFERENTIATION. METHODS: TO ASSESS DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 DURING GOBLET CELL DIFFERENTIATION, PRIMARY AIRWAY EPITHELIAL CELLS, ISOLATED FROM TRACHEA (NON-COPD CONTROLS) AND BRONCHIAL TISSUE (PATIENTS WITH COPD), WERE DIFFERENTIATED BY CULTURE AT THE AIR-LIQUID INTERFACE (ALI) IN THE PRESENCE OF CYTOKINE INTERLEUKIN (IL)-13 TO PROMOTE GOBLET CELL DIFFERENTIATION. RESULTS: WE FOUND THAT SPDEF EXPRESSION WAS INDUCED DURING GOBLET CELL DIFFERENTIATION, WHILE FOXA2 EXPRESSION WAS DECREASED. IMPORTANTLY, CPG NUMBER 8 IN THE SPDEF PROMOTER WAS HYPERMETHYLATED UPON DIFFERENTIATION, WHEREAS DNA METHYLATION OF FOXA2 PROMOTER WAS NOT CHANGED. IN THE ABSENCE OF IL-13, COPD-DERIVED ALI-CULTURED CELLS DISPLAYED HIGHER SPDEF EXPRESSION THAN CONTROL-DERIVED ALI CULTURES, WHEREAS NO DIFFERENCE WAS FOUND FOR FOXA2 EXPRESSION. THIS WAS ACCOMPANIED WITH HYPOMETHYLATION OF CPG NUMBER 6 IN THE SPDEF PROMOTER AND ALSO HYPOMETHYLATION OF CPG NUMBERS 10 AND 11 IN THE FOXA2 PROMOTER. CONCLUSIONS: THESE FINDINGS SUGGEST THAT ABERRANT DNA METHYLATION OF SPDEF AND FOXA2 IS ONE OF THE FACTORS UNDERLYING MUCUS HYPERSECRETION IN COPD, OPENING NEW AVENUES FOR EPIGENETIC-BASED INHIBITION OF MUCUS HYPERSECRETION. 2017 12 11 33 15Q12 VARIANTS, SPUTUM GENE PROMOTER HYPERMETHYLATION, AND LUNG CANCER RISK: A GWAS IN SMOKERS. BACKGROUND: LUNG CANCER IS THE LEADING CAUSE OF CANCER-RELATED MORTALITY WORLDWIDE. DETECTION OF PROMOTER HYPERMETHYLATION OF TUMOR SUPPRESSOR GENES IN EXFOLIATED CELLS FROM THE LUNG PROVIDES AN ASSESSMENT OF FIELD CANCERIZATION THAT IN TURN PREDICTS LUNG CANCER. THE IDENTIFICATION OF GENETIC DETERMINANTS FOR THIS VALIDATED CANCER BIOMARKER SHOULD PROVIDE NOVEL INSIGHTS INTO MECHANISMS UNDERLYING EPIGENETIC REPROGRAMMING DURING LUNG CARCINOGENESIS. METHODS: A GENOME-WIDE ASSOCIATION STUDY USING GENERALIZED ESTIMATING EQUATIONS AND LOGISTIC REGRESSION MODELS WAS CONDUCTED IN TWO GEOGRAPHICALLY INDEPENDENT SMOKER COHORTS TO IDENTIFY LOCI AFFECTING THE PROPENSITY FOR CANCER-RELATED GENE METHYLATION THAT WAS ASSESSED BY A 12-GENE PANEL INTERROGATED IN SPUTUM. ALL STATISTICAL TESTS WERE TWO-SIDED. RESULTS: TWO SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) AT 15Q12 (RS73371737 AND RS7179575) THAT DROVE GENE METHYLATION WERE DISCOVERED AND REPLICATED WITH RS73371737 REACHING GENOME-WIDE SIGNIFICANCE (P = 3.3X10(-8)). A HAPLOTYPE CARRYING RISK ALLELES FROM THE TWO 15Q12 SNPS CONFERRED 57% INCREASED RISK FOR GENE METHYLATION (P = 2.5X10(-9)). RS73371737 REDUCED GABRB3 EXPRESSION IN LUNG CELLS AND INCREASED RISK FOR SMOKING-INDUCED CHRONIC MUCOUS HYPERSECRETION. FURTHERMORE, SUBJECTS WITH VARIANT HOMOZYGOTE OF RS73371737 HAD A TWO-FOLD INCREASE IN RISK FOR LUNG CANCER (P = .0043). PATHWAY ANALYSIS IDENTIFIED DNA DOUBLE-STRAND BREAK REPAIR BY HOMOLOGOUS RECOMBINATION (DSBR-HR) AS A MAJOR PATHWAY AFFECTING SUSCEPTIBILITY FOR GENE METHYLATION THAT WAS VALIDATED BY MEASURING CHROMATID BREAKS IN LYMPHOCYTES CHALLENGED BY BLEOMYCIN. CONCLUSIONS: A FUNCTIONAL 15Q12 VARIANT WAS IDENTIFIED AS A RISK FACTOR FOR GENE METHYLATION AND LUNG CANCER. THE ASSOCIATIONS COULD BE MEDIATED BY GABAERGIC SIGNALING THAT DRIVES THE SMOKING-INDUCED MUCOUS CELL METAPLASIA. OUR FINDINGS ALSO SUBSTANTIATE DSBR-HR AS A CRITICAL PATHWAY DRIVING EPIGENETIC GENE SILENCING. 2015 13 172 40 ABSENCE OF HDAC3 BY MATRIX STIFFNESS PROMOTES CHROMATIN REMODELING AND FIBROBLAST ACTIVATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC AND FATAL DISEASE CHARACTERIZED BY PROGRESSIVE AND IRREVERSIBLE LUNG SCARRING ASSOCIATED WITH PERSISTENT ACTIVATION OF FIBROBLASTS. EPIGENETICS COULD INTEGRATE DIVERSE MICROENVIRONMENTAL SIGNALS, SUCH AS STIFFNESS, TO DIRECT PERSISTENT FIBROBLAST ACTIVATION. HISTONE MODIFICATIONS BY DEACETYLASES (HDAC) MAY PLAY AN ESSENTIAL ROLE IN THE GENE EXPRESSION CHANGES INVOLVED IN THE PATHOLOGICAL REMODELING OF THE LUNG. PARTICULARLY, HDAC3 IS CRUCIAL FOR MAINTAINING CHROMATIN AND REGULATING GENE EXPRESSION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN IPF. IN THE STUDY, CONTROL AND IPF-DERIVED FIBROBLASTS WERE USED TO DETERMINE THE INFLUENCE OF HDAC3 ON CHROMATIN REMODELING AND GENE EXPRESSION ASSOCIATED WITH IPF SIGNATURE. ADDITIONALLY, THE CELLS WERE GROWN ON HYDROGELS TO MIMIC THE STIFFNESS OF A FIBROTIC LUNG. OUR RESULTS SHOWED A DECREASED HDAC3 IN THE NUCLEUS OF IPF FIBROBLASTS, WHICH CORRELATES WITH CHANGES IN NUCLEUS SIZE AND HETEROCHROMATIN LOSS. THE INHIBITION OF HDAC3 WITH A PHARMACOLOGICAL INHIBITOR CAUSES HYPERACETYLATION OF H3K9 AND PROVOKES AN INCREASED EXPRESSION OF COL1A1, ACTA2, AND P21. COMPARABLE RESULTS WERE FOUND IN HYDROGELS, WHERE MATRIX STIFFNESS PROMOTES THE LOSS OF NUCLEAR HDAC3 AND INCREASES THE PROFIBROTIC SIGNATURE. FINALLY, LATRUNCULIN B WAS USED TO CONFIRM THAT CHANGES BY STIFFNESS DEPEND ON THE MECHANOTRANSDUCTION SIGNALS. TOGETHER, THESE RESULTS SUGGEST THAT HDAC3 COULD BE A LINK BETWEEN EPIGENETIC MECHANISMS AND THE FIBROTIC MICROENVIRONMENT. 2023 14 3939 30 LNC-IL7R ALLEVIATES PM(2.5)-MEDIATED CELLULAR SENESCENCE AND APOPTOSIS THROUGH EZH2 RECRUITMENT IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE. BACKGROUND: LONG-TERM EXPOSURE TO PM(2.5) (PARTICULATE MATTER WITH AN AERODYNAMIC DIAMETER OF