1 3924 92 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 2 5695 40 SILENCING UHRF1 ENHANCES CELL AUTOPHAGY TO PREVENT ARTICULAR CHONDROCYTES FROM APOPTOSIS IN OSTEOARTHRITIS THROUGH PI3K/AKT/MTOR SIGNALING PATHWAY. OSTEOARTHRITIS (OA) IS A COMMON CHRONIC DEGENERATIVE JOINT DISEASE, AND CHONDROCYTE APOPTOSIS IS ONE OF MOST IMPORTANT PATHOLOGICAL CHANGES OF OA PATHOGENESIS. GROWING STUDIES HAVE SHOWN THAT UBIQUITIN-LIKE WITH PHD AND RING FINGER DOMAINS 1 (UHRF1) IS AN IMPORTANT EPIGENETIC REGULATORY FACTOR THAT REGULATES CELL PROLIFERATION AND APOPTOSIS OF VARIOUS TUMORS, BUT ITS ROLE IN OA REMAINS ILL-DEFINED. IN THE PRESENT STUDY, WE FOUND THAT UHRF1 EXPRESSION WAS INCREASED IN HUMAN OA CARTILAGE TISSUES, COMPARED WITH NORMAL CARTILAGE TISSUES. INTERLEUKIN-1BETA (IL-1BETA), A MAJOR INFLAMMATORY CYTOKINE THAT PROMOTES CARTILAGE DEGRADATION IN OA, WAS USED TO STIMULATE PRIMARY HUMAN CHONDROCYTES IN VITRO. THE EXPRESSION OF UHRF1 WAS ALSO ENHANCED IN IL-1BETA-INDUCED CHONDROCYTES. MOREOVER, DOWN-REGULATION OF UHRF1 INDUCED AN INCREASE ON CELL PROLIFERATION AND AUTOPHAGY, AND A DECREASE ON APOPTOSIS OF CHONDROCYTES AFTER IL-1BETA TREATMENT. FURTHER DATA INDICATED THAT SILENCING UHRF1 ATTENUATED THE UP-REGULATION OF IL-1BETA ON PHOSPHOINOSITIDE 3-KINASE (PI3K)/PROTEIN KINASE B (AKT)/MAMMALIAN TARGET OF RAPAMYCIN (MTOR) SIGNALING PATHWAY IN CHONDROCYTES. THEN, AN ACTIVATOR OF PI3K WEAKENED THE EFFECT OF UHRF1 SILENCING ON CELL PROLIFERATION, AUTOPHAGY, APOPTOSIS OF IL-1BETA-INDUCED CHONDROCYTES, AND THE CELL AUTOPHAGY SPECIAL INHIBITOR 3-METHYLADENINE (3-MA) ALSO SHOWED A SAME IMPACT ON UHRF1, HENCE SUGGESTING THAT KNOCKDOWN OF UHRF1 ENHANCES CELL AUTOPHAGY TO PROTECT CHONDROCYTES FROM APOPTOSIS IN OA THROUGH PI3K/AKT/MTOR SIGNALING PATHWAY. IN CONCLUSION, OUR STUDY SUGGESTS THAT UHRF1 MAY BE A POTENTIAL REGULATOR OF CHONDROCYTE APOPTOSIS IN THE PATHOGENESIS OF OA. 2020 3 2384 31 EPIGENETIC REGULATOR UHRF1 ORCHESTRATES PROINFLAMMATORY GENE EXPRESSION IN RHEUMATOID ARTHRITIS IN A SUPPRESSIVE MANNER. RHEUMATOID ARTHRITIS (RA) IS CHARACTERIZED BY CHRONIC SYNOVIAL INFLAMMATION WITH ABERRANT EPIGENETIC ALTERATIONS, EVENTUALLY LEADING TO JOINT DESTRUCTION. HOWEVER, THE EPIGENETIC REGULATORY MECHANISMS UNDERLYING RA PATHOGENESIS REMAIN LARGELY UNKNOWN. HERE, WE SHOWED THAT UBIQUITIN-LIKE CONTAINING PHD AND RING FINGER DOMAINS 1 (UHRF1) IS A CENTRAL EPIGENETIC REGULATOR THAT ORCHESTRATES MULTIPLE PATHOGENESES IN RA IN A SUPPRESSIVE MANNER. UHRF1 EXPRESSION WAS REMARKABLY UPREGULATED IN SYNOVIAL FIBROBLASTS (SFS) FROM ARTHRITIS MODEL MICE AND PATIENTS WITH RA. MICE WITH SF-SPECIFIC UHRF1 CONDITIONAL KNOCKOUT SHOWED MORE SEVERE ARTHRITIC PHENOTYPES THAN LITTERMATE CONTROLS. UHRF1-DEFICIENT SFS ALSO EXHIBITED ENHANCED APOPTOSIS RESISTANCE AND UPREGULATED EXPRESSION OF SEVERAL CYTOKINES, INCLUDING CCL20. IN PATIENTS WITH RA, DAS28, CRP, AND TH17 ACCUMULATION AND APOPTOSIS RESISTANCE WERE NEGATIVELY CORRELATED WITH UHRF1 EXPRESSION IN SYNOVIUM. FINALLY, RYUVIDINE ADMINISTRATION STABILIZED UHRF1 AMELIORATED ARTHRITIS PATHOGENESES IN A MOUSE MODEL OF RA. THIS STUDY DEMONSTRATED THAT UHRF1 EXPRESSED IN RA SFS CAN CONTRIBUTE TO NEGATIVE FEEDBACK MECHANISMS THAT SUPPRESS MULTIPLE PATHOGENIC EVENTS IN ARTHRITIS, SUGGESTING THAT TARGETING UHRF1 COULD BE ONE OF THE THERAPEUTIC STRATEGIES FOR RA. 2022 4 5995 29 TGFBETA-INDUCED FIBROBLAST ACTIVATION REQUIRES PERSISTENT AND TARGETED HDAC-MEDIATED GENE REPRESSION. TISSUE FIBROSIS IS A CHRONIC DISEASE DRIVEN BY PERSISTENT FIBROBLAST ACTIVATION THAT HAS RECENTLY BEEN LINKED TO EPIGENETIC MODIFICATIONS. HERE, WE SCREENED A SMALL LIBRARY OF EPIGENETIC SMALL-MOLECULE MODULATORS TO IDENTIFY COMPOUNDS CAPABLE OF INHIBITING OR REVERSING TGFBETA-MEDIATED FIBROBLAST ACTIVATION. WE IDENTIFIED PRACINOSTAT, AN HDAC INHIBITOR, AS A POTENT ATTENUATOR OF LUNG FIBROBLAST ACTIVATION AND CONFIRMED ITS EFFICACY IN PATIENT-DERIVED FIBROBLASTS ISOLATED FROM FIBROTIC LUNG TISSUE. MECHANISTICALLY, WE FOUND THAT HDAC-DEPENDENT TRANSCRIPTIONAL REPRESSION WAS AN EARLY AND ESSENTIAL EVENT IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION. TREATMENT OF LUNG FIBROBLASTS WITH PRACINOSTAT BROADLY ATTENUATED TGFBETA-MEDIATED EPIGENETIC REPRESSION AND PROMOTED FIBROBLAST QUIESCENCE. WE CONFIRMED A SPECIFIC ROLE FOR HDAC-DEPENDENT HISTONE DEACETYLATION IN THE PROMOTER REGION OF THE ANTI-FIBROTIC GENE PPARGC1A (PGC1ALPHA) IN RESPONSE TO TGFBETA STIMULATION. FINALLY, WE IDENTIFIED HDAC7 AS A KEY FACTOR WHOSE SIRNA-MEDIATED KNOCKDOWN ATTENUATES FIBROBLAST ACTIVATION WITHOUT ALTERING GLOBAL HISTONE ACETYLATION. TOGETHER, THESE RESULTS PROVIDE NOVEL MECHANISTIC INSIGHT INTO THE ESSENTIAL ROLE HDACS PLAY IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION VIA TARGETED GENE REPRESSION. 2019 5 4362 25 MIR?152 REGULATES TGF?BETA1?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION BY TARGETING HPIP IN TUBULAR EPITHELIAL CELLS. RENAL FIBROSIS IS A COMMON PATHOLOGICAL FEATURE OF CHRONIC KIDNEY DISEASES, AND THEIR DEVELOPMENT AND PROGRESSION ARE INFLUENCED BY EPIGENETIC MODIFICATIONS INCLUDING ABERRANT MICRORNA (MIRNA OR MIR) EXPRESSION. MIRNAS HAVE BEEN DEMONSTRATED TO MODULATE THE AGGRESSIVENESS OF VARIOUS CANCERS AND HAVE EMERGED AS POSSIBLE THERAPEUTIC AGENTS FOR THE MANAGEMENT OF RENAL FIBROSIS. TRANSFORMING GROWTH FACTOR BETA1 (TGF?BETA1)?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION (EMT) OF TUBULAR EPITHELIAL CELLS SERVES A ROLE IN THE INITIATION AND PROGRESSION OF RENAL FIBROSIS. FURTHERMORE, RECENT RESULTS INDICATED THAT THE PROGRESSION OF EMT IS REVERSIBLE. THE PRESENT STUDY AIMED TO CLARIFY THE ROLE OF MIR?152 IN EMT OF THE TUBULAR EPITHELIAL CELL LINE HK?2, STIMULATED BY TGF?BETA1, USING IN VITRO TRANSFECTION WITH A MIR?152 MIMIC AND TO FURTHER INVESTIGATE THE UNDERLYING MECHANISM OF MIR?152 ACTIVITY. IN THE PRESENT STUDY, MIR?152 EXPRESSION WAS SIGNIFICANTLY REDUCED IN TGF?BETA1?TREATED HK?2 CELLS, ACCOMPANIED BY AN INCREASED EXPRESSION OF HEMATOPOIETIC PRE?B?CELL LEUKEMIA TRANSCRIPTION FACTOR (PBX)?INTERACTING PROTEIN (HPIP). ADDITIONALLY, MIR?152 OVEREXPRESSION INHIBITED TGF?BETA1?INDUCED EMT AND SUPPRESSED HPIP EXPRESSION BY DIRECTLY TARGETING THE 3' UNTRANSLATED REGION OF HPIP IN HK?2 CELLS. FURTHERMORE, UPREGULATION OF HPIP REVERSED MIR?152?MEDIATED INHIBITORY EFFECTS ON THE EMT. COLLECTIVELY, THE RESULTS SUGGEST THAT DOWNREGULATION OF MIR?152 INITIATES THE DEDIFFERENTIATION OF RENAL TUBULES AND PROGRESSION OF RENAL FIBROSIS, WHICH MAY PROVIDE IMPORTANT TARGETS FOR PREVENTION STRATEGIES OF RENAL FIBROSIS. 2018 6 6611 35 UHRF1 REGULATES GERMINAL CENTER B CELL EXPANSION AND AFFINITY MATURATION TO CONTROL VIRAL INFECTION. THE PRODUCTION OF HIGH-AFFINITY ANTIBODY IS ESSENTIAL FOR PATHOGEN CLEARANCE. ANTIBODY AFFINITY IS INCREASED THROUGH GERMINAL CENTER (GC) AFFINITY MATURATION, WHICH RELIES ON BCR SOMATIC HYPERMUTATION (SHM) FOLLOWED BY ANTIGEN-BASED SELECTION. GC B CELL PROLIFERATION IS ESSENTIALLY INVOLVED IN THESE PROCESSES; IT PROVIDES ENOUGH TEMPLATES FOR SHM AND ALSO SERVES AS A CRITICAL MECHANISM OF POSITIVE SELECTION. IN THIS STUDY, WE SHOW THAT EXPRESSION OF EPIGENETIC REGULATOR UBIQUITIN-LIKE WITH PHD AND RING FINGER DOMAINS 1 (UHRF1) WAS MARKEDLY UP-REGULATED BY C-MYC-AP4 IN GC B CELLS, AND IT WAS REQUIRED FOR GC RESPONSE. UHRF1 REGULATES CELL PROLIFERATION-ASSOCIATED GENES INCLUDING CDKN1A, SLFN1, AND SLFN2 BY DNA METHYLATION, AND ITS DEFICIENCY INHIBITED THE GC B CELL CYCLE AT G1-S PHASE. SUBSEQUENTLY, GC B CELL SHM AND AFFINITY MATURATION WERE IMPAIRED, AND UHRF1 GC B KNOCKOUT MICE WERE UNABLE TO CONTROL CHRONIC VIRUS INFECTION. COLLECTIVELY, OUR DATA SUGGEST THAT UHRF1 REGULATES GC B CELL PROLIFERATION AND AFFINITY MATURATION, AND ITS EXPRESSION IN GC B CELLS IS REQUIRED FOR VIRUS CLEARANCE. 2018 7 5088 30 PIPERLONGUMINE REGULATES EPIGENETIC MODULATION AND ALLEVIATES PSORIASIS-LIKE SKIN INFLAMMATION VIA INHIBITION OF HYPERPROLIFERATION AND INFLAMMATION. PSORIASIS IS AN AUTOIMMUNE SKIN DISEASE, WHERE CHRONIC IMMUNE RESPONSES DUE TO EXAGGERATED CYTOKINE SIGNALING, ABNORMAL DIFFERENTIATION, AND EVASION OF KERATINOCYTES APOPTOSIS PLAYS A CRUCIAL ROLE IN MEDIATING ABNORMAL KERATINOCYTES HYPERPROLIFERATION. FROM THE THERAPEUTIC PERSPECTIVE, THE MOLECULES WITH STRONG ANTI-PROLIFERATIVE AND ANTI-INFLAMMATORY PROPERTIES COULD HAVE TREMENDOUS RELEVANCE. IN THIS STUDY, WE DEMONSTRATED THAT PIPERLONGUMINE (PPL) TREATMENT EFFECTIVELY ABROGATED THE HYPERPROLIFERATION AND DIFFERENTIATION OF KERATINOCYTES BY INDUCING ROS-MEDIATED LATE APOPTOSIS WITH LOSS OF MITOCHONDRIAL MEMBRANE POTENTIAL. BESIDES, THE ARREST OF CELL CYCLE WAS FOUND AT SUB-G1 PHASE AS A RESULT OF DNA FRAGMENTATION. MOLECULARLY, INHIBITION OF STAT3 AND AKT SIGNALING WAS OBSERVED WITH A DECREASE IN PROLIFERATIVE MARKERS SUCH AS PCNA, KI67, AND CYCLIN D1 ALONG WITH ANTI-APOPTOTIC BCL-2 PROTEIN EXPRESSION. KERATIN 17 IS A CRITICAL REGULATOR OF KERATINOCYTE DIFFERENTIATION, AND IT WAS FOUND TO BE DOWNREGULATED WITH PPL SIGNIFICANTLY. FURTHERMORE, PROMINENT ANTI-INFLAMMATORY EFFECTS WERE OBSERVED BY INHIBITION OF LIPOPOLYSACCHARIDE (LPS)/IMIQUIMOD (IMQ)-INDUCED P65 NF-KAPPAB SIGNALING CASCADE AND STRONGLY INHIBITED THE PRODUCTION OF CYTOKINE STORM INVOLVED IN PSORIASIS-LIKE SKIN INFLAMMATION, THUS LED TO THE RESTORATION OF NORMAL EPIDERMAL ARCHITECTURE WITH REDUCTION OF EPIDERMAL HYPERPLASIA AND SPLENOMEGALY. IN ADDITION, PPL EPIGENETICALLY INHIBITED HISTONE-MODIFYING ENZYMES, WHICH INCLUDE HISTONE DEACETYLASES (HDACS) OF CLASS I (HDAC1-4) AND CLASS II (HDAC6) EVALUATED BY IMMUNOBLOTTING AND HDAC ENZYME ASSAY KIT. IN ADDITION, OUR RESULTS SHOW THAT PPL EFFECTIVELY INHIBITS THE NUCLEAR TRANSLOCATION OF P65 AND A HISTONE MODULATOR HDAC3, THUS SEQUESTERED IN THE CYTOPLASM OF MACROPHAGES. FURTHERMORE, PPL EFFECTIVELY ENHANCED THE PROTEIN-PROTEIN INTERACTIONS OF HDAC3 AND P65 WITH IKAPPABALPHA, WHICH WAS DISRUPTED BY LPS STIMULATION AND WERE EVALUATED BY CO-IP AND MOLECULAR MODELING. COLLECTIVELY, OUR FINDINGS INDICATE THAT PIPERLONGUMINE MAY SERVE AS AN ANTI-PROLIFERATIVE AND ANTI-INFLAMMATORY AGENT AND COULD SERVE AS A POTENTIAL THERAPEUTIC OPTION IN TREATING PSORIASIS. 2020 8 164 30 ABNORMAL HISTONE METHYLATION IS RESPONSIBLE FOR INCREASED VASCULAR ENDOTHELIAL GROWTH FACTOR 165A SECRETION FROM AIRWAY SMOOTH MUSCLE CELLS IN ASTHMA. VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), A KEY ANGIOGENIC MOLECULE, IS ABERRANTLY EXPRESSED IN SEVERAL DISEASES INCLUDING ASTHMA WHERE IT CONTRIBUTES TO BRONCHIAL VASCULAR REMODELING AND CHRONIC INFLAMMATION. ASTHMATIC HUMAN AIRWAY SMOOTH MUSCLE CELLS HYPERSECRETE VEGF, BUT THE MECHANISM IS UNCLEAR. IN THIS STUDY, WE DEFINED THE MECHANISM IN HUMAN AIRWAY SMOOTH MUSCLE CELLS FROM NONASTHMATIC AND ASTHMATIC PATIENTS. WE FOUND THAT ASTHMATIC CELLS LACKED A REPRESSION COMPLEX AT THE VEGF PROMOTER, WHICH WAS PRESENT IN NONASTHMATIC CELLS. RECRUITMENT OF G9A, TRIMETHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME3), AND A RESULTANT DECREASE IN RNA POLYMERASE II AT THE VEGF PROMOTER WAS CRITICAL TO REPRESSION OF VEGF SECRETION IN NONASTHMATIC CELLS. AT THE ASTHMATIC PROMOTER, H3K9ME3 WAS ABSENT BECAUSE OF FAILED RECRUITMENT OF G9A; RNA POLYMERASE II BINDING, IN ASSOCIATION WITH TATA-BINDING PROTEIN-ASSOCIATED FACTOR 1, WAS INCREASED; H3K4ME3 WAS PRESENT; AND SP1 BINDING WAS EXAGGERATED AND SUSTAINED. IN CONTRAST, DNA METHYLATION AND HISTONE ACETYLATION WERE SIMILAR IN ASTHMATIC AND NONASTHMATIC CELLS. THIS IS THE FIRST STUDY, TO OUR KNOWLEDGE, TO SHOW THAT AIRWAY CELLS IN ASTHMA HAVE ALTERED EPIGENETIC REGULATION OF REMODELING GENE(S). HISTONE METHYLATION AT GENES SUCH AS VEGF MAY BE AN IMPORTANT NEW THERAPEUTIC TARGET. 2012 9 5972 21 TET REPRESSION AND INCREASED DNMT ACTIVITY SYNERGISTICALLY INDUCE ABERRANT DNA METHYLATION. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN VARIOUS HUMAN DISORDERS, SUCH AS CANCER, NEURODEGENERATIVE DISORDERS, AND METABOLIC DISORDERS. INDUCTION OF EPIGENETIC ALTERATIONS, ESPECIALLY ABERRANT DNA METHYLATION, IS ONE OF THE MAJOR MECHANISMS, BUT HOW IT IS INDUCED IS STILL UNCLEAR. HERE, WE FOUND THAT EXPRESSION OF TET GENES, METHYLATION ERASERS, WAS DOWNREGULATED IN INFLAMED MOUSE AND HUMAN TISSUES, AND THAT THIS WAS CAUSED BY UPREGULATION OF TET-TARGETING MIRNAS SUCH AS MIR20A, MIR26B, AND MIR29C, LIKELY DUE TO ACTIVATION OF NF-KAPPAB SIGNALING DOWNSTREAM OF IL-1BETA AND TNF-ALPHA. HOWEVER, TET KNOCKDOWN INDUCED ONLY MILD ABERRANT METHYLATION. NITRIC OXIDE (NO), PRODUCED BY NOS2, ENHANCED ENZYMATIC ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), METHYLATION WRITERS, AND NO EXPOSURE INDUCED MINIMAL ABERRANT METHYLATION. IN CONTRAST, A COMBINATION OF TET KNOCKDOWN AND NO EXPOSURE SYNERGISTICALLY INDUCED ABERRANT METHYLATION, INVOLVING GENOMIC REGIONS NOT METHYLATED BY EITHER ALONE. THE RESULTS SHOWED THAT A VICIOUS COMBINATION OF TET REPRESSION, DUE TO NF-KAPPAB ACTIVATION, AND DNMT ACTIVATION, DUE TO NO PRODUCTION, IS RESPONSIBLE FOR ABERRANT METHYLATION INDUCTION IN HUMAN TISSUES. 2020 10 1902 24 ENHANCED EXPRESSION OF THE NUCLEAR ENVELOPE LAP2 TRANSCRIPTIONAL REPRESSORS IN NORMAL AND MALIGNANT ACTIVATED LYMPHOCYTES. EXTENSIVE RESEARCH IN RECENT YEARS HAS BROADENED THE FUNCTIONS OF NUCLEAR ENVELOPE PROTEINS BEYOND SIMPLY STABILIZING THE NUCLEUS ARCHITECTURE. PARTICULARLY, INTEGRAL NUCLEAR MEMBRANE PROTEINS, SUCH AS THE ALTERNATIVE SPLICED ISOFORMS OF LAMINA-ASSOCIATED POLYPEPTIDE 2 (LAP2), HAVE BEEN SHOWN TO BE IMPORTANT FOR THE INITIATION OF REPLICATION AND REPRESSION OF TRANSCRIPTION. THE LATTER IS REGULATED BY EPIGENETIC CHANGES, INDUCED BY THE BINDING OF LAP2BETA TO HISTONE DEACETYLASE-3 (HDAC3), RESULTING IN HISTONE H4 DEACETYLATION. INVOLVEMENT OF NUCLEAR ENVELOPE PROTEINS IN PATHOLOGICAL PROLIFERATIVE CONDITIONS, MAINLY THOSE INVOLVING ABNORMAL RECRUITMENT AND ACTIVATION OF HDACS, IS STILL UNKNOWN. IN THIS PAPER, WE SHOW THAT VARIOUS NUCLEAR ENVELOPE PROTEINS ARE HIGHLY EXPRESSED IN NORMAL AND MALIGNANT ACTIVATED LYMPHOCYTES. SPECIFICALLY, RAPIDLY REPLICATING CELLS OF VARIOUS HEMATOLOGICAL MALIGNANCIES HIGHLY EXPRESS LAP2BETA, WHILE SLOWLY PROLIFERATING MALIGNANT CELLS OF CHRONIC MALIGNANT HEMATOLOGICAL DISEASES DO NOT. TAKING TOGETHER THE ELEVATED EXPRESSION OF LAP2BETA IN HIGHLY PROLIFERATIVE MALIGNANT CELLS WITH ITS KNOWN ABILITY TO MODIFY HISTONES THROUGH BINDING WITH HDAC3 RAISES THE POSSIBILITY OF ITS ROLE IN HEMATOLOGICAL MALIGNANCIES INVOLVING ABERRANT ACTIVITY OF HDAC3. BASED ON OUR PRESENTED RESULTS, WE BELIEVE THAT THE LAP2-HDAC REGULATORY PATHWAY SHOULD BE STUDIED AS A NEW TARGET FOR RATIONAL THERAPY. 2007 11 3527 26 IL-6 ENHANCES THE NUCLEAR TRANSLOCATION OF DNA CYTOSINE-5-METHYLTRANSFERASE 1 (DNMT1) VIA PHOSPHORYLATION OF THE NUCLEAR LOCALIZATION SEQUENCE BY THE AKT KINASE. THE EPIGENETIC PROGRAMMING OF GENOMIC DNA IS ACCOMPLISHED, IN PART, BY SEVERAL DNA CYTOSINE-5-METHYLTRANSFERASES THAT ACT BY COVALENTLY MODIFYING CYTOSINES WITH THE ADDITION OF A METHYL GROUP. THIS COVALENT MODIFICATION IS MAINTAINED BY THE DNA CYTOSINE-5-METHYLTRANSFERASE-1 ENZYME (DNMT1), WHICH IS CAPABLE OF ACTING IN CONCERT WITH OTHER SIMILAR ENZYMES TO SILENCE IMPORTANT TUMOR SUPPRESSOR GENES. IL-6 IS A MULTIFUNCTIONAL MEDIATOR OF INFLAMMATION, ACTING THROUGH SEVERAL MAJOR SIGNALING CASCADES, INCLUDING THE PHOSPHATIDYLINOSITOL-3-KINASE PATHWAY (PI-3-K), WHICH ACTIVATES PROTEIN KINASE B (AKT/PKB) DOWNSTREAM. HERE, WE SHOW THAT THE SUBCELLULAR LOCALIZATION OF DNMT1 CAN BE ALTERED BY THE ADDITION OF IL-6, INCREASING THE RATE OF NUCLEAR TRANSLOCATION OF THE ENZYME FROM THE CYTOSOLIC COMPARTMENT. THE MECHANISM OF NUCLEAR TRANSLOCATION OF DNMT1 IS GREATLY ENHANCED BY PHOSPHORYLATION OF THE DNMT1 NUCLEAR LOCALIZATION SIGNAL (NLS) BY PKB/AKT KINASE. MUTAGENIC ALTERATION OF THE TWO AKT TARGET AMINO ACIDS WITHIN THE NLS RESULTS IN A MAJOR LOSS OF DNMT1 NUCLEAR TRANSLOCATION, WHILE THE CREATION OF A "PHOSPHO-MIMIC" AMINO ACID (MUTATION TO ACIDIC RESIDUES) RESTORES THIS COMPARTMENTATION ABILITY. THESE OBSERVATIONS SUGGEST AN INTERESTING HYPOTHESIS REGARDING HOW MEDIATORS OF CHRONIC INFLAMMATION MAY DISTURB THE DELICATE BALANCE OF CELLULAR COMPARTMENTALIZATION OF IMPORTANT PROTEINS, AND REVEALS A POTENTIAL MECHANISM FOR THE INDUCTION OR ENHANCEMENT OF TUMOR GROWTH VIA ALTERATION OF THE COMPONENTS INVOLVED IN THE EPIGENETIC PROGRAMMING OF A CELL. 2007 12 172 33 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 13 3351 32 HISTONE DEMETHYLASE JARID1B REGULATES PROLIFERATION AND MIGRATION OF PULMONARY ARTERIAL SMOOTH MUSCLE CELLS IN MICE WITH CHRONIC HYPOXIA-INDUCED PULMONARY HYPERTENSION VIA NUCLEAR FACTOR-KAPPA B (NFKB). CHRONIC HYPOXIA-INDUCED PULMONARY HYPERTENSION (PH) IS A DISORDER THAT IS CHARACTERIZED BY INCREASED PULMONARY ARTERIAL PRESSURE RESULTING FROM LUNG DISEASES OR SHORTAGE OF OXYGEN IN THE BODY. EXCESS PROLIFERATION OF PULMONARY VASCULAR CELLS SUCH AS PULMONARY ARTERY ENDOTHELIAL CELLS (PAECS) AND PULMONARY ARTERY SMOOTH MUSCLE CELLS (PASMCS) PLAYS A CRITICAL ROLE IN THE PATHOGENESIS OF PH. RECENT EVIDENCE INDICATES THAT, IN ADDITION TO GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS, EPIGENETIC MECHANISMS PLAY A PIVOTAL ROLE IN ETIOLOGY OF PH. IN THIS STUDY, WE INVESTIGATED THE POSSIBLE ROLE PLAYED BY JUMONJI AT-RICH INTERACTIVE DOMAIN 1B (JARID1B), A HISTONE DEMETHYLASE, IN REGULATING THE PROLIFERATION OF VASCULAR SMOOTH MUSCLE CELLS IN CHRONIC HYPOXIA-INDUCED PH CONDITION. QUANTITATIVE POLYMERASE CHAIN REACTION ANALYSIS OF SAMPLES FROM RATS WITH PH SHOWED AN ELEVATED EXPRESSION OF JARID1B IN THEIR PASMCS, POSITIVELY CORRELATING WITH INCREASED NUCLEAR FACTOR-KAPPA B (NFKB) EXPRESSION. FURTHER FUNCTIONAL STUDIES IN VITRO INDICATED THAT OVEREXPRESSION OF JARID1B INCREASED THE PROLIFERATION AND MIGRATION OF PASMCS, WHICH WERE INHIBITED BY DEPLETION OF NFKB. GENOMEWIDE TRANSCRIPTIONAL ANALYSIS REVEALED THAT THE JARID1B REGULATED NFKB SIGNALING PATHWAY BY DIRECTLY BINDING TO ITS PROMOTER. WE HAVE ALSO SHOWN THAT JARID1B INDIRECTLY REGULATES THE EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR VIA NFKB SIGNALING AND HENCE MAY ALSO PLAY A CRUCIAL ROLE IN CONTROLLING PAECS, LEADING TO CHANGES IN VASCULAR ARCHITECTURE IN PH. OUR FINDINGS COULD LEAD TO FURTHER STUDIES ON THE ROLE OF JARID1B IN PH ETIOLOGY AND THEREFORE COULD LEAD TO A POTENTIAL THERAPEUTIC TARGET FOR CHRONIC HYPOXIA INDUCED PULMONARY HYPERTENSION. 2018 14 3628 25 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 15 3468 38 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 16 5571 24 ROLE OF MICRORNA 1207-5P AND ITS HOST GENE, THE LONG NON-CODING RNA PVT1, AS MEDIATORS OF EXTRACELLULAR MATRIX ACCUMULATION IN THE KIDNEY: IMPLICATIONS FOR DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY IS THE MOST COMMON CAUSE OF CHRONIC KIDNEY FAILURE AND END-STAGE RENAL DISEASE IN THE WESTERN WORLD. ONE OF THE MAJOR CHARACTERISTICS OF THIS DISEASE IS THE EXCESSIVE ACCUMULATION OF EXTRACELLULAR MATRIX (ECM) IN THE KIDNEY GLOMERULI. WHILE BOTH ENVIRONMENTAL AND GENETIC DETERMINANTS ARE RECOGNIZED FOR THEIR ROLE IN THE DEVELOPMENT OF DIABETIC NEPHROPATHY, EPIGENETIC FACTORS, SUCH AS DNA METHYLATION, LONG NON-CODING RNAS, AND MICRORNAS, HAVE ALSO RECENTLY BEEN FOUND TO UNDERLIE SOME OF THE BIOLOGICAL MECHANISMS, INCLUDING ECM ACCUMULATION, LEADING TO THE DISEASE. WE PREVIOUSLY FOUND THAT A LONG NON-CODING RNA, THE PLASMACYTOMA VARIANT TRANSLOCATION 1 (PVT1), INCREASES PLASMINOGEN ACTIVATOR INHIBITOR 1 (PAI-1) AND TRANSFORMING GROWTH FACTOR BETA 1 (TGF-BETA1) IN MESANGIAL CELLS, THE TWO MAIN CONTRIBUTORS TO ECM ACCUMULATION IN THE GLOMERULI UNDER HYPERGLYCEMIC CONDITIONS, AS WELL AS FIBRONECTIN 1 (FN1), A MAJOR ECM COMPONENT. HERE, WE REPORT THAT MIR-1207-5P, A PVT1-DERIVED MICRORNA, IS ABUNDANTLY EXPRESSED IN KIDNEY CELLS, AND IS UPREGULATED BY GLUCOSE AND TGF-BETA1. WE ALSO FOUND THAT LIKE PVT1, MIR-1207-5P INCREASES EXPRESSION OF TGF-BETA1, PAI-1, AND FN1 BUT IN A MANNER THAT IS INDEPENDENT OF ITS HOST GENE. IN ADDITION, REGULATION OF MIR-1207-5P EXPRESSION BY GLUCOSE AND TGFBETA1 IS INDEPENDENT OF PVT1. THESE RESULTS PROVIDE EVIDENCE SUPPORTING IMPORTANT ROLES FOR MIR-1207-5P AND ITS HOST GENE IN THE COMPLEX PATHOGENESIS OF DIABETIC NEPHROPATHY. 2013 17 1615 27 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 18 3193 27 HDAC INHIBITION REGULATES OXIDATIVE STRESS IN CD4(+)THELPER CELLS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND NON-SMALL CELL LUNG CANCER PATIENTS VIA MITOCHONDRIAL TRANSCRIPTION FACTOR A (MTTFA) MODULATING NF-KAPPAB/HIF1ALPHA AXIS. HISTONE DEACETYLASES (HDACS) PLAY A CRUCIAL ROLE IN THE EPIGENETIC REGULATION OF GENE EXPRESSION BY REMODELLING CHROMATIN. ISOENZYMES OF THE HDAC FAMILY EXHIBIT ABERRANT REGULATION IN A WIDE VARIETY OF CANCERS AS WELL AS SEVERAL INFLAMMATORY LUNG DISORDERS LIKE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). INHIBITION OF HDACS IS A POTENTIAL THERAPEUTIC STRATEGY THAT COULD BE USED TO REVERSE EPIGENETIC MODIFICATION. TRICHOSTATIN A (TSA), A POWERFUL HISTONE DEACETYLASE (HDAC) INHIBITOR, HAS ANTI-CANCER EFFECTS IN NUMEROUS CANCER TYPES. HOWEVER, IT IS NOT YET APPARENT HOW HDAC INHIBITORS AFFECT HUMAN NON-SMALL CELL LUNG CANCER CELLS (NSCLC) AND COPD. THIS STUDY AIMS TO INVESTIGATE TSA'S ROLE IN RESTORING MITOCHONDRIAL DYSFUNCTION AND ITS EFFECT ON HYPOXIA AND INFLAMMATION IN CD4(+)T CELLS OBTAINED FROM PATIENTS WITH COPD AND LUNG CANCER. AS A RESULT OF TREATMENT WITH TSA, THERE IS A REDUCTION IN THE EXPRESSION OF INFLAMMATORY CYTOKINES AND A DECREASED ENRICHMENT OF TRANSCRIPTIONAL FACTORS ASSOCIATED WITH INFLAMMATION AT VEGFA GENE LOCI. WE HAVE SEEN A SUBSTANTIAL DECREASE IN THE EXPRESSION OF NF-KAPPAB AND HIF1ALPHA, WHICH ARE THE CRITICAL MEDIATORS OF INFLAMMATION AND HYPOXIA, RESPECTIVELY. FOLLOWING TSA TREATMENT, MTTFA EXPRESSION WAS INCREASED, FACILITATING PATIENTS WITH COPD AND NSCLC IN THE RECOVERY OF THEIR DYSFUNCTIONAL MITOCHONDRIA. FURTHERMORE, WE HAVE DISCOVERED THAT TSA TREATMENT IN PATIENTS WITH COPD AND NSCLC MAY LEAD TO IMMUNOPROTECTIVE NESS BY INDUCING TH1NESS. OUR FINDING GIVES A NEW INSIGHT INTO THE EXISTING BODY OF KNOWLEDGE REGARDING TSA-BASED THERAPEUTIC METHODS AND HIGHLIGHTS THE NECESSITY OF EPIGENETIC THERAPY FOR THESE DEVASTATING LUNG DISORDERS. 2023 19 5920 23 TARGETING CHROMATIN REMODELING IN INFLAMMATION AND FIBROSIS. MUCOSAL SURFACES OF THE HUMAN BODY ARE LINED BY A CONTIGUOUS EPITHELIAL CELL SURFACE THAT FORMS A BARRIER TO AEROSOLIZED PATHOGENS. SPECIALIZED PATTERN RECOGNITION RECEPTORS DETECT THE PRESENCE OF VIRAL PATHOGENS AND INITIATE PROTECTIVE HOST RESPONSES BY TRIGGERING ACTIVATION OF THE NUCLEAR FACTOR KAPPAB (NFKAPPAB)/RELA TRANSCRIPTION FACTOR AND FORMATION OF A COMPLEX WITH THE POSITIVE TRANSCRIPTION ELONGATION FACTOR (P-TEFB)/CYCLIN-DEPENDENT KINASE (CDK)9 AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) EPIGENETIC READER. THE RELA.BRD4.P-TEFB COMPLEX PRODUCES ACUTE INFLAMMATION BY REGULATING TRANSCRIPTIONAL ELONGATION, WHICH PRODUCES A RAPID GENOMIC RESPONSE BY INACTIVE GENES MAINTAINED IN AN OPEN CHROMATIN CONFIGURATION ENGAGED WITH HYPOPHOSPHORYLATED RNA POLYMERASE II. WE DESCRIBE RECENT STUDIES THAT HAVE LINKED PROLONGED ACTIVATION OF THE RELA-BRD4 PATHWAY WITH THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT) BY INDUCING A CORE OF EMT COREPRESSORS, STIMULATING SECRETION OF GROWTH FACTORS PROMOTING AIRWAY FIBROSIS. THE MESENCHYMAL STATE PRODUCES REWIRING OF THE KINOME AND REPROGRAMMING OF INNATE RESPONSES TOWARD INFLAMMATION. IN ADDITION, THE CORE REGULATOR ZINC FINGER E-BOX HOMEODOMAIN 1 (ZEB1) SILENCES THE EXPRESSION OF THE INTERFERON RESPONSE FACTOR 1 (IRF1), REQUIRED FOR TYPE III IFN EXPRESSION. THIS EPIGENETIC SILENCING IS MEDIATED BY THE ENHANCER OF ZESTE 2 (EZH2) HISTONE METHYLTRANSFERASE. BECAUSE OF THEIR POTENTIAL APPLICATIONS IN CANCER AND INFLAMMATION, SMALL-MOLECULE INHIBITORS OF NFKAPPAB/RELA, CDK9, BRD4, AND EZH2 HAVE BEEN THE TARGETS OF MEDICINAL CHEMISTRY EFFORTS. WE SUGGEST THAT DISRUPTION OF THE RELA.BRD4.P-TEFB PATHWAY AND EZH2 METHYLTRANSFERASE HAS IMPORTANT IMPLICATIONS FOR REVERSING FIBROSIS AND RESTORING NORMAL MUCOSAL IMMUNITY IN CHRONIC INFLAMMATORY DISEASES. 2017 20 2025 24 EPIGENETIC CHANGES DURING DISEASE PROGRESSION IN A MURINE MODEL OF HUMAN CHRONIC LYMPHOCYTIC LEUKEMIA. EPIGENETIC ALTERATIONS, INCLUDING GAIN OR LOSS OF DNA METHYLATION, ARE A HALLMARK OF NEARLY EVERY MALIGNANCY. CHANGES IN DNA METHYLATION CAN IMPACT EXPRESSION OF CANCER-RELATED GENES INCLUDING APOPTOSIS REGULATORS AND TUMOR SUPPRESSORS. BECAUSE SUCH EPIGENETIC CHANGES ARE REVERSIBLE, THEY ARE BEING AGGRESSIVELY INVESTIGATED AS POTENTIAL THERAPEUTIC TARGETS. HERE WE USE THE EMU-TCL1 TRANSGENIC MOUSE MODEL OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) TO DETERMINE THE TIMING AND PATTERNS OF ABERRANT DNA METHYLATION, AND TO INVESTIGATE THE MECHANISMS THAT LEAD TO ABERRANT DNA METHYLATION. WE SHOW THAT CLL CELLS FROM EMU-TCL1 MICE AT VARIOUS STAGES RECAPITULATE EPIGENETIC ALTERATIONS SEEN IN HUMAN CLL. ABERRANT METHYLATION OF PROMOTER SEQUENCES IS OBSERVED AS EARLY AS 3 MONTHS OF AGE IN THESE ANIMALS, WELL BEFORE DISEASE ONSET. ABNORMALLY METHYLATED PROMOTER REGIONS INCLUDE BINDING SITES FOR THE TRANSCRIPTION FACTOR FOXD3. WE SHOW THAT LOSS OF FOXD3 EXPRESSION DUE TO AN NF-KAPPAB P50/P50:HDAC1 REPRESSOR COMPLEX OCCURS IN TCL1-POSITIVE B CELLS BEFORE METHYLATION. THEREFORE, SPECIFIC TRANSCRIPTIONAL REPRESSION IS AN EARLY EVENT LEADING TO EPIGENETIC SILENCING OF TARGET GENES IN MURINE AND HUMAN CLL. THESE RESULTS PROVIDE STRONG RATIONALE FOR THE DEVELOPMENT OF STRATEGIES TO TARGET NF-KAPPAB COMPONENTS IN CLL AND POTENTIALLY OTHER B-CELL MALIGNANCIES. 2009