1 2425 108 EPIGENETIC SILENCING OF IRF1 DYSREGULATES TYPE III INTERFERON RESPONSES TO RESPIRATORY VIRUS INFECTION IN EPITHELIAL TO MESENCHYMAL TRANSITION. CHRONIC OXIDATIVE INJURY PRODUCED BY AIRWAY DISEASE TRIGGERS A TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA)-MEDIATED EPIGENETIC REPROGRAMMING KNOWN AS THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). WE OBSERVE THAT EMT SILENCES PROTECTIVE MUCOSAL INTERFERON (IFN)-I AND III PRODUCTION ASSOCIATED WITH ENHANCED RHINOVIRUS (RV) AND RESPIRATORY SYNCYTIAL VIRUS (RSV) REPLICATION. MESENCHYMAL TRANSITIONED CELLS ARE DEFECTIVE IN INDUCIBLE INTERFERON REGULATORY FACTOR 1 (IRF1) EXPRESSION BY OCCLUDING RELA AND IRF3 ACCESS TO THE PROMOTER. IRF1 IS NECESSARY FOR THE EXPRESSION OF TYPE III IFNS (IFNLS 1 AND 2/3). INDUCED BY THE EMT, ZINC FINGER E-BOX BINDING HOMEOBOX 1 (ZEB1) BINDS AND SILENCES IRF1. ECTOPIC ZEB1 IS SUFFICIENT FOR IRF1 SILENCING, WHEREAS ZEB1 KNOCKDOWN PARTIALLY RESTORES IRF1-IFNL UPREGULATION. ZEB1 SILENCES IRF1 THROUGH THE CATALYTIC ACTIVITY OF THE ENHANCER OF ZESTE 2 POLYCOMB REPRESSIVE COMPLEX 2 SUBUNIT (EZH2), FORMING REPRESSIVE H3K27(ME3) MARKS. WE OBSERVE THAT IRF1 EXPRESSION IS MEDIATED BY ZEB1 DE-REPRESSION, AND OUR STUDY DEMONSTRATES HOW AIRWAY REMODELLING/FIBROSIS IS ASSOCIATED WITH A DEFECTIVE MUCOSAL ANTIVIRAL RESPONSE THROUGH ZEB1-INITIATED EPIGENETIC SILENCING. 2017 2 1632 28 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 3 6235 26 THE M(6)A DEMETHYLASE FTO PROMOTES RENAL EPITHELIAL-MESENCHYMAL TRANSITION BY REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. BACKGROUND: RENAL INTERSTITIAL FIBROSIS (RIF) IS THE MAIN PATHOLOGICAL CHANGE OF A VARIETY OF CHRONIC KIDNEY DISEASES (CKD). EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE RIF PROGRESSION. THIS STUDY AIMED TO INVESTIGATE LONG NON-CODING RNA (LNCRNA) N6-METHYLADENOSINE (M(6)A) MODIFICATION AND ITS ROLE IN REGULATING RIF PROGRESSION. METHODS: UNILATERAL URETERAL OCCLUSION (UUO) WAS EMPLOYED TO CONSTRUCT THE RIF IN VIVO MODEL; AND TGF-BETA1-TREATED HK-2 AND HKC-8 CELLS WERE USED FOR IN VITRO EXPERIMENTS. THE MRNA AND PROTEIN EXPRESSIONS WERE ASSESSED USING QRT-PCR AND WESTERN BLOT. THE PROLIFERATION AND MIGRATION WERE EVALUATED BY EDU ASSAY AND TRANSWELL ASSAY, RESPECTIVELY. IN ADDITION, LEVELS OF INFLAMMATORY CYTOKINES WERE DETERMINED BY ELISA ASSAY AND QRT-PCR. MOREOVER, LNCRNA GAS5 M(6)A LEVEL WAS DETECTED USING ME-RIP ASSAY. HE AND MASSON STAINING WERE EMPLOYED TO EVALUATE FIBROTIC LESIONS OF THE KIDNEY. RESULTS: FTO EXPRESSION WAS ELEVATED IN HK-2 AND HKC-8 CELLS AFTER TGF-BETA1 TREATMENT AND MOUSE KIDNEY TISSUE FOLLOWING UUO, AND LNCRNA GAS5 WAS DOWNREGULATED. LNCRNA GAS5 OVEREXPRESSION OR FTO SILENCING SUPPRESSED TGF-BETA1-INDUCED THE INCREASE OF EMT-RELATED PROTEINS (VIMENTIN, SNAIL AND N-CADHERIN) AND INFLAMMATORY CYTOKINES (IL-6, IL-1BETA AND TNF-ALPHA) LEVELS IN HK-2 CELLS. FTO SUPPRESSED LNCRNA GAS5 EXPRESSION BY REDUCING THE M6A MODIFICATION OF LNCRNA GAS5. ADDITIONALLY, FTO KNOCKDOWN COULD SUPPRESS EMT PROCESS AND INFLAMMATION RESPONSE INDUCED BY TGF-BETA1 AND UUO IN VITRO AND IN VIVO. AS EXPECTED, FTO KNOCKDOWN ABROGATED THE PROMOTION EFFECTS OF LNCRNA GAS5 SILENCING ON TGF-BETA1-INDUCED EMT PROCESS AND INFLAMMATION RESPONSE IN HK-2 AND HKC-8 CELLS. CONCLUSION: FTO PROMOTED EMT PROCESS AND INFLAMMATION RESPONSE THROUGH REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. 2022 4 922 26 CHRONIC IL-1BETA-INDUCED INFLAMMATION REGULATES EPITHELIAL-TO-MESENCHYMAL TRANSITION MEMORY PHENOTYPES VIA EPIGENETIC MODIFICATIONS IN NON-SMALL CELL LUNG CANCER. CHRONIC INFLAMMATION FACILITATES TUMOR PROGRESSION. WE DISCOVERED THAT A SUBSET OF NON-SMALL CELL LUNG CANCER CELLS UNDERWENT A GRADUALLY PROGRESSING EPITHELIAL-TO-MESENCHYMAL (EMT) PHENOTYPE FOLLOWING A 21-DAY EXPOSURE TO IL-1BETA, AN ABUNDANT PROINFLAMMATORY CYTOKINE IN THE AT-RISK FOR LUNG CANCER PULMONARY AND THE LUNG TUMOR MICROENVIRONMENTS. PATHWAY ANALYSIS OF THE GENE EXPRESSION PROFILE AND IN VITRO FUNCTIONAL STUDIES REVEALED THAT THE EMT AND EMT-ASSOCIATED PHENOTYPES, INCLUDING ENHANCED CELL INVASION, PD-L1 UPREGULATION, AND CHEMORESISTANCE, WERE SUSTAINED IN THE ABSENCE OF CONTINUOUS IL-1BETA EXPOSURE. WE REFERRED TO THIS PHENOMENON AS EMT MEMORY. UTILIZING A DOXYCYCLINE-CONTROLLED SLUG EXPRESSION SYSTEM, WE FOUND THAT HIGH EXPRESSION OF THE TRANSCRIPTION FACTOR SLUG WAS INDISPENSABLE FOR THE ESTABLISHMENT OF EMT MEMORY. HIGH SLUG EXPRESSION IN TUMORS OF LUNG CANCER PATIENTS WAS ASSOCIATED WITH POOR SURVIVAL. CHEMICAL OR GENETIC INHIBITION OF SLUG UPREGULATION PREVENTED EMT FOLLOWING THE ACUTE IL-1BETA EXPOSURE BUT DID NOT REVERSE EMT MEMORY. CHROMATIN IMMUNOPRECIPITATION AND METHYLATION-SPECIFIC PCR FURTHER REVEALED A SLUG-MEDIATED TEMPORAL REGULATION OF EPIGENETIC MODIFICATIONS, INCLUDING ACCUMULATION OF H3K27, H3K9, AND DNA METHYLATION, IN THE CDH1 (E-CADHERIN) PROMOTER FOLLOWING THE CHRONIC IL-1BETA EXPOSURE. CHEMICAL INHIBITION OF DNA METHYLATION NOT ONLY RESTORED E-CADHERIN EXPRESSION IN EMT MEMORY, BUT ALSO PRIMED CELLS FOR CHEMOTHERAPY-INDUCED APOPTOSIS. 2020 5 5850 28 SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) REDUCES FIBROSIS MARKERS AND DEACTIVATES HUMAN STELLATE CELLS VIA THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). HEPATIC FIBROSIS IS KNOWN AS THE ACCUMULATION OF CONNECTIVE TISSUE SECONDARY TO CHRONIC DAMAGE TO THE LIVER. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) CORRESPONDING INCREASE IN LIVER FIBROGENESIS WAS SHOWN WITH IMMUNOHISTOCHEMISTRY AND PCR-BASED STUDIES. SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), A SYNTHETIC COMPOUND APPROVED AS A HISTONE DEACETYLASE INHIBITOR (HDAC) BY THE FDA TO TREAT CUTANEOUS T-CELL LYMPHOMA IS UNDER INVESTIGATION FOR THE TREATMENT OF LUNG AND RENAL FIBROSIS. EXPERIMENTAL MODELING FOR HEPATIC FIBROSIS CAN BE CONSTRUCTED WITH AN LX2 CELL LINE ISOLATED FROM HUMAN HEPATIC STELLATE CELLS (HSCS). IN THIS STUDY, WE AIMED TO INVESTIGATE THE MODULATION OF SAHA IN THE PATHOGENESIS OF LIVER FIBROSIS BY DETECTING THE LEVELS OF PROTEINS; (E-CADHERIN (E-CAD), N-CADHERIN (N-CAD), VIMENTIN (VIM), AND GENES; E-CAD, N-CAD, VIM, TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA), ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), TYPE 1 COLLAGEN (COL1A1), TYPE 3 COLLAGEN (COL3A1)) THAT PLAY A SIGNIFICANT ROLE IN EMT WITH THE LX2 CELL LINE. WE ALSO EVALUATED THE ACTION OF SAHA WITH CELL PROLIFERATION, CLONOGENIC, AND MIGRATION ASSAY. CELL PROLIFERATION WAS PERFORMED BY FLOW CYTOMETRY. ALL THE PROTEIN LEVELS WERE DETERMINED BY WESTERN BLOT ANALYSIS, AND GENE EXPRESSION LEVELS WERE MEASURED BY REAL-TIME PCR. OUR STUDY OBSERVED THAT SAHA TREATMENT DECREASED CELL VIABILITY, COLONY FORMATION AND MIGRATION IN LX2 CELLS. WE FOUND THAT SAHA INCREASED E-CAD EXPRESSION LEVEL, WHILE IT DECREASED N-CAD, VIM, COL1A1, COL3A1, ALPHA-SMA TGF-BETA GENES EXPRESSION LEVELS. SAHA DECREASED THE LEVEL OF E-CAD, N-CAD, AND VIM PROTEIN LEVELS. WE THOUGHT THAT SAHA POSSESSES POTENT ANTIFIBROTIC AND ANTI-EMT PROPERTIES IN LX2. 2021 6 3289 28 HIF-1ALPHA MEDIATES TUMOR HYPOXIA TO CONFER A PERPETUAL MESENCHYMAL PHENOTYPE FOR MALIGNANT PROGRESSION. ALTHOUGH TUMOR PROGRESSION INVOLVES GENETIC AND EPIGENETIC ALTERATIONS TO NORMAL CELLULAR BIOLOGY, THE UNDERLYING MECHANISMS OF THESE CHANGES REMAIN OBSCURE. NUMEROUS STUDIES HAVE SHOWN THAT HYPOXIA-INDUCIBLE FACTOR 1ALPHA (HIF-1ALPHA) IS OVEREXPRESSED IN MANY HUMAN CANCERS AND UP-REGULATES A HOST OF HYPOXIA-RESPONSIVE GENES FOR CANCER GROWTH AND SURVIVAL. WE RECENTLY IDENTIFIED AN ALTERNATIVE MECHANISM OF HIF-1ALPHA FUNCTION THAT INDUCES GENETIC ALTERATIONS BY SUPPRESSING DNA REPAIR. HERE, WE SHOW THAT LONG-TERM HYPOXIA, WHICH MIMICS THE TUMOR MICROENVIRONMENT, DRIVES A PERPETUAL EPITHELIAL-MESENCHYMAL TRANSITION (EMT) THROUGH UP-REGULATION OF THE ZINC FINGER E-BOX BINDING HOMEOBOX PROTEIN ZEB2, WHEREAS SHORT-TERM HYPOXIA INDUCES A REVERSIBLE EMT THAT REQUIRES THE TRANSCRIPTION FACTOR TWIST1. MOREOVER, WE SHOW THAT THE PERPETUAL EMT DRIVEN BY CHRONIC HYPOXIA DEPENDS ON HIF-1ALPHA INDUCTION OF GENETIC ALTERATIONS RATHER THAN ITS CANONICAL TRANSCRIPTIONAL ACTIVATOR FUNCTION. THESE MESENCHYMAL TUMOR CELLS NOT ONLY ACQUIRE TUMORIGENICITY BUT ALSO DISPLAY CHARACTERISTICS OF ADVANCED CANCERS, INCLUDING NECROSIS, AGGRESSIVE INVASION, AND METASTASIS. HENCE, THESE RESULTS REVEAL A MECHANISM BY WHICH HIF-1ALPHA PROMOTES A PERPETUAL MESENCHYMAL PHENOTYPE, THEREBY ADVANCING TUMOR PROGRESSION. 2011 7 6232 34 THE LONG NONCODING RNA MEG3 REGULATES MYOBLAST PLASTICITY AND MUSCLE REGENERATION THROUGH EPITHELIAL-MESENCHYMAL TRANSITION. FORMATION OF SKELETAL MUSCLE IS AMONG THE MOST STRIKING EXAMPLES OF CELLULAR PLASTICITY IN ANIMAL TISSUE DEVELOPMENT, AND WHILE MUSCLE PROGENITOR CELLS ARE REPROGRAMMED BY EPITHELIAL-MESENCHYMAL TRANSITION (EMT) TO MIGRATE DURING EMBRYONIC DEVELOPMENT, THE REGULATION OF EMT IN POST-NATAL MYOGENESIS REMAINS POORLY UNDERSTOOD. HERE, WE DEMONSTRATE THAT THE LONG NONCODING RNA (LNCRNA) MEG3 REGULATES EMT IN MYOBLAST DIFFERENTIATION AND SKELETAL MUSCLE REGENERATION. CHRONIC INHIBITION OF MEG3 IN C2C12 MYOBLASTS INDUCED EMT, AND SUPPRESSED CELL STATE TRANSITIONS REQUIRED FOR DIFFERENTIATION. FURTHERMORE, ADENOVIRAL MEG3 KNOCKDOWN COMPROMISED MUSCLE REGENERATION, WHICH WAS ACCOMPANIED BY ABNORMAL MESENCHYMAL GENE EXPRESSION AND INTERSTITIAL CELL PROLIFERATION. TRANSCRIPTOMIC AND PATHWAY ANALYSES OF MEG3-DEPLETED C2C12 MYOBLASTS AND INJURED SKELETAL MUSCLE REVEALED A SIGNIFICANT DYSREGULATION OF EMT-RELATED GENES, AND IDENTIFIED TGFBETA AS A KEY UPSTREAM REGULATOR. IMPORTANTLY, INHIBITION OF TGFBETAR1 AND ITS DOWNSTREAM EFFECTORS, AND THE EMT TRANSCRIPTION FACTOR SNAI2, RESTORED MANY ASPECTS OF MYOGENIC DIFFERENTIATION IN MEG3-DEPLETED MYOBLASTS IN VITRO WE FURTHER DEMONSTRATE THAT REDUCTION OF MEG3-DEPENDENT EZH2 ACTIVITY RESULTS IN EPIGENETIC ALTERATIONS ASSOCIATED WITH TGFBETA ACTIVATION. THUS, MEG3 REGULATES MYOBLAST IDENTITY TO FACILITATE PROGRESSION INTO DIFFERENTIATION. 2021 8 4661 19 NEW ASPECTS OF THE EPIGENETIC REGULATION OF EMT RELATED TO PULMONARY FIBROSIS. PULMONARY FIBROSIS IS A CHRONIC AND PROGRESSIVE FIBROTIC DISEASE THAT RESULTS IN IMPAIRED GAS EXCHANGE, VENTILATION, AND EVENTUAL DEATH. THE PRO-FIBROTIC ENVIRONMENT IS INSTIGATED BY VARIOUS FACTORS, LEADING TO THE TRANSFORMATION OF EPITHELIAL CELLS INTO MYOFIBROBLASTS AND/OR FIBROBLASTS THAT TRIGGER FIBROSIS. EPITHELIAL MESENCHYMAL TRANSITION (EMT) IS A BIOLOGICAL PROCESS THAT PLAYS A CRITICAL ROLE IN THE PATHOGENESIS OF PULMONARY FIBROSIS. EPIGENETIC REGULATION OF TISSUE-STROMAL CROSSTALK INVOLVING DNA METHYLATION, HISTONE MODIFICATIONS, NON-CODING RNA, AND CHROMATIN REMODELING PLAYS A KEY ROLE IN THE CONTROL OF EMT. THE REVIEW INVESTIGATES THE EPIGENETIC REGULATION OF EMT AND ITS SIGNIFICANCE IN PULMONARY FIBROSIS. 2023 9 866 32 CHRONIC ACTIVATION OF MUC1-C IN WOUND REPAIR PROMOTES PROGRESSION TO CANCER STEM CELLS. THE MUCIN 1 (MUC1) GENE EMERGED IN MAMMALS TO AFFORD PROTECTION OF BARRIER EPITHELIAL TISSUES FROM THE EXTERNAL ENVIRONMENT. MUC1 ENCODES A TRANSMEMBRANE C-TERMINAL (MUC1-C) SUBUNIT THAT IS ACTIVATED BY LOSS OF HOMEOSTASIS AND INDUCES INFLAMMATORY, PROLIFERATIVE, AND REMODELING PATHWAYS ASSOCIATED WITH WOUND REPAIR. AS A CONSEQUENCE, CHRONIC ACTIVATION OF MUC1-C PROMOTES LINEAGE PLASTICITY, EPIGENETIC REPROGRAMMING, AND CARCINOGENESIS. IN DRIVING CANCER PROGRESSION, MUC1-C IS IMPORTED INTO THE NUCLEUS, WHERE IT INDUCES NF-KAPPAB INFLAMMATORY SIGNALING AND THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). MUC1-C REPRESSES GENE EXPRESSION BY ACTIVATING (I) DNA METHYLTRANSFERASE 1 (DNMT1) AND DNMT3B, (II) POLYCOMB REPRESSIVE COMPLEX 1 (PRC1) AND PRC2, AND (III) THE NUCLEOSOME REMODELING AND DEACETYLASE (NURD) COMPLEX. PRC1/2-MEDIATED GENE REPRESSION IS COUNTERACTED BY THE SWI/SNF CHROMATIN REMODELING COMPLEXES. MUC1-C ACTIVATES THE SWI/SNF BAF AND PBAF COMPLEXES IN CANCER STEM CELL (CSC) MODELS WITH THE INDUCTION OF GENOME-WIDE DIFFERENTIALLY ACCESSIBLE REGIONS AND EXPRESSED GENES. MUC1-C REGULATES CHROMATIN ACCESSIBILITY OF ENHANCER-LIKE SIGNATURES IN ASSOCIATION WITH THE INDUCTION OF THE YAMANAKA PLURIPOTENCY FACTORS AND RECRUITMENT OF JUN AND BAF, WHICH PROMOTE INCREASES IN HISTONE ACTIVATION MARKS AND OPENING OF CHROMATIN. THESE AND OTHER FINDINGS DESCRIBED IN THIS REVIEW HAVE UNCOVERED A PIVOTAL ROLE FOR MUC1-C IN INTEGRATING LINEAGE PLASTICITY AND EPIGENETIC REPROGRAMMING, WHICH ARE TRANSIENT IN WOUND REPAIR AND SUSTAINED IN PROMOTING CSC PROGRESSION. 2022 10 4700 28 NICKEL EXPOSURE INDUCES PERSISTENT MESENCHYMAL PHENOTYPE IN HUMAN LUNG EPITHELIAL CELLS THROUGH EPIGENETIC ACTIVATION OF ZEB1. NICKEL (NI) IS AN ENVIRONMENTAL AND OCCUPATIONAL CARCINOGEN, AND EXPOSURE TO NI IS ASSOCIATED WITH LUNG AND NASAL CANCERS IN HUMANS. FURTHERMORE, NI EXPOSURE IS IMPLICATED IN SEVERAL LUNG DISEASES INCLUDING CHRONIC INFLAMMATORY AIRWAY DISEASES, ASTHMA, AND FIBROSIS. HOWEVER, THE MUTAGENIC POTENTIAL OF NI IS LOW AND DOES NOT CORRELATE WITH ITS POTENT TOXICITY AND CARCINOGENICITY. THEREFORE, MECHANISMS UNDERLYING NI EXPOSURE-ASSOCIATED DISEASES REMAIN POORLY UNDERSTOOD. SINCE THE HEALTH RISKS OF ENVIRONMENTAL EXPOSURES OFTEN CONTINUE POST EXPOSURE, UNDERSTANDING THE EXPOSURE EFFECTS THAT PERSIST AFTER THE TERMINATION OF EXPOSURE COULD PROVIDE MECHANISTIC INSIGHTS INTO DISEASES. BY EXAMINING THE PERSISTENT EFFECTS OF NI EXPOSURE, WE REPORT THAT NI INDUCES EPITHELIAL-MESENCHYMAL TRANSITION (EMT) AND THAT THE MESENCHYMAL PHENOTYPE REMAINS IRREVERSIBLE EVEN AFTER THE TERMINATION OF EXPOSURE. NI-INDUCED EMT WAS DEPENDENT ON THE IRREVERSIBLE UPREGULATION OF ZEB1, AN EMT MASTER REGULATOR, VIA RESOLUTION OF ITS PROMOTER BIVALENCY. ZEB1, UPON ACTIVATION, DOWNREGULATED ITS REPRESSORS AS WELL AS THE CELL-CELL ADHESION MOLECULE, E-CADHERIN, RESULTING IN THE CELLS UNDERGOING EMT AND SWITCHING TO PERSISTENT MESENCHYMAL STATUS. ZEB1 DEPLETION IN CELLS EXPOSED TO NI ATTENUATED NI-INDUCED EMT. MOREOVER, NI EXPOSURE DID NOT INDUCE EMT IN ZEB1-DEPLETED CELLS. ACTIVATION OF EMT, DURING WHICH THE EPITHELIAL CELLS LOSE CELL-CELL ADHESION AND BECOME MIGRATORY AND INVASIVE, PLAYS A MAJOR ROLE IN ASTHMA, FIBROSIS, AND CANCER AND METASTASIS, LUNG DISEASES ASSOCIATED WITH NI EXPOSURE. THEREFORE, OUR FINDING OF IRREVERSIBLE EPIGENETIC ACTIVATION OF ZEB1 BY NI EXPOSURE AND THE ACQUISITION OF PERSISTENT MESENCHYMAL PHENOTYPE WOULD HAVE IMPORTANT IMPLICATIONS IN UNDERSTANDING NI-INDUCED DISEASES. 2018 11 95 26 A POSSIBLE ROLE FOR EPIGENETIC FEEDBACK REGULATION IN THE DYNAMICS OF THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT) OFTEN PLAYS A CRITICAL ROLE IN CANCER METASTASIS AND CHEMORESISTANCE, AND DECODING ITS DYNAMICS IS CRUCIAL TO DESIGN EFFECTIVE THERAPEUTICS. EMT IS REGULATED AT MULTIPLE LEVELS-TRANSCRIPTIONAL, TRANSLATIONAL, PROTEIN STABILITY AND EPIGENETICS; THE MECHANISMS BY WHICH EPIGENETIC REGULATION CAN ALTER THE DYNAMICS OF EMT REMAIN ELUSIVE. HERE, TO IDENTIFY THE POSSIBLE EFFECTS OF EPIGENETIC REGULATION IN EMT, WE INCORPORATE A FEEDBACK TERM IN OUR PREVIOUSLY PROPOSED MODEL OF EMT REGULATION OF THE MIR-200/ZEB/MIR-34/SNAIL CIRCUIT. THIS EPIGENETIC FEEDBACK THAT STABILIZES LONG-TERM TRANSCRIPTIONAL ACTIVITY CAN ALTER THE RELATIVE STABILITY AND DISTRIBUTION OF STATES IN A GIVEN CELL POPULATION, PARTICULARLY WHEN INCORPORATED IN THE INHIBITORY EFFECT ON MIR-200 FROM ZEB. THIS FEEDBACK CAN STABILIZE THE MESENCHYMAL STATE, THUS MAKING TRANSITIONS OUT OF THAT STATE DIFFICULT. CONVERSELY, EPIGENETIC REGULATION OF THE SELF-ACTIVATION OF ZEB HAS ONLY MINOR EFFECTS. OUR MODEL PREDICTS THAT THIS EFFECT COULD BE SEEN IN EXPERIMENTS, WHEN EPITHELIAL CELLS ARE TREATED WITH AN EXTERNAL EMT-INDUCING SIGNAL FOR A SUFFICIENTLY LONG PERIOD OF TIME AND THEN ALLOWED TO RECOVER. OUR PRELIMINARY EXPERIMENTAL DATA INDICATES THAT A CHRONIC TGF-BETA EXPOSURE GIVES RISE TO IRREVEVERSIBLE EMT STATE; I.E. UNABLE TO REVERSE BACK TO THE EPITHELIAL STATE. THUS, THIS INTEGRATED THEORETICAL-EXPERIMENTAL APPROACH YIELDS INSIGHTS INTO HOW AN EPIGENETIC FEEDBACK MAY ALTER THE DYNAMICS OF EMT. 2019 12 4362 29 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 13 3036 32 GENISTEIN AMELIORATES RENAL FIBROSIS THROUGH REGULATION SNAIL VIA M6A RNA DEMETHYLASE ALKBH5. RENAL TUBULE-INTERSTITIAL FIBROSIS IS RELATED TO CHRONIC KIDNEY DISEASE PROGRESSION AND A TYPICAL FEATURE OF THE AGING KIDNEY. EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE THE DEVELOPMENT OF RENAL FIBROSIS. AS A KIND OF "EPIGENETIC DIET", SOY ISOFLAVONE GENISTEIN WAS REPORTED TO HAVE RENAL PROTECTIVE ACTION AND EPIGENETIC-MODULATING EFFECTS. HOWEVER, ITS RENAL PROTECTION ROLE AND UNDERLYING MECHANISMS ARE YET TO BE FULLY CLARIFIED. HEREIN, WE SHOWED THAT GENISTEIN EXHIBITS A DEMONSTRABLE ANTI-FIBROTIC EFFECT ON KIDNEY IN VIVO UUO (UNILATERAL URETERAL OCCLUSION) MODEL AND RENAL EPITHELIAL CELLS IN VITRO MODEL. THE MECHANISM IS STRONGLY ASSOCIATED WITH EPITHELIAL-TO-MESENCHYMAL TRANSITION AND M6A RNA DEMETHYLASE ALKBH5. MOUSE FIBROTIC KIDNEYS INDUCED BY UUO EXHIBITED ADVERSE EXPRESSION OF RENAL FIBROSIS-RELATED PROTEINS AND SIGNIFICANT INCREASES IN THE TOTAL M6A LEVEL. AS AN ERASER, ALKBH5 SHOWED SEVERER SUPPRESSION IN THE RENAL FIBROSIS PROCESS. HOWEVER, GENISTEIN PRETREATMENT RESTORED ALKBH5 LOSS REMARKABLY AND REDUCED RENAL FIBROSIS, ABNORMAL PROTEIN, AND INFLAMMATORY MARKERS. THE EXAMINATION OF POSSIBLE MECHANISMS REVEALED THAT GENISTEIN PROMOTED ALKBH5 AND MAYBE INDUCED THE LEVEL OF MRNA M6A METHYLATION IN SOME EPITHELIAL-TO-MESENCHYMAL TRANSITION-RELATED TRANSCRIPTION FACTORS. WE FOUND SNAIL WAS THE CRITICAL REGULATOR AND CRITICAL FOR THE PROTECTIVE ROLE OF GENISTEIN. TO VERIFY THE RELATIONSHIP BETWEEN ALKBH5 AND SNAIL, WE GENERATED KNOCKDOWN AND OVEREXPRESSION OF ALKBH5 CELLS IN VITRO. ALKBH5 KNOCKDOWN ENHANCED THE MESENCHYMAL PHENOTYPE MARKER ALPHA-SMOOTH MUSCLE ACTIN AND SNAIL EXPRESSION. IN AGREEMENT, OVEREXPRESSION ALKBH5 INCREASED EPITHELIAL ADHESION MOLECULE E-CADHERIN AND REDUCED SNAIL EXPRESSION. IN CONCLUSION, GENISTEIN INCREASED RENAL ALKBH5 EXPRESSION IN UUO-INDUCED RENAL FIBROSIS AND REDUCED RNA M6A LEVELS AND AMELIORATES RENAL DAMAGES. 2020 14 2334 24 EPIGENETIC REGULATION OF INFLAMMATORY CYTOKINE-INDUCED EPITHELIAL-TO-MESENCHYMAL CELL TRANSITION AND CANCER STEM CELL GENERATION. THE NEOPLASTIC TRANSFORMATION OF NORMAL TO METASTATIC CANCER CELLS IS A COMPLEX MULTISTEP PROCESS INVOLVING THE PROGRESSIVE ACCUMULATION OF INTERACTING GENETIC AND EPIGENETIC CHANGES THAT ALTER GENE FUNCTION AND AFFECT CELL PHYSIOLOGY AND HOMEOSTASIS. EPIGENETIC CHANGES INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND CHANGES IN NONCODING RNA EXPRESSION, AND DEREGULATION OF EPIGENETIC PROCESSES CAN ALTER GENE EXPRESSION DURING THE MULTISTEP PROCESS OF CARCINOGENESIS. CANCER PROGRESSION AND METASTASIS THROUGH AN 'INVASION-METASTASIS CASCADE' INVOLVING AN EPITHELIAL-TO-MESENCHYMAL CELL TRANSITION (EMT), THE GENERATION OF CANCER STEM CELLS (CSCS), INVASION OF ADJACENT TISSUES, AND DISSEMINATION ARE FUELED BY INFLAMMATION, WHICH IS CONSIDERED A HALLMARK OF CANCER. CHRONIC INFLAMMATION IS GENERATED BY INFLAMMATORY CYTOKINES SECRETED BY THE TUMOR AND THE TUMOR-ASSOCIATED CELLS WITHIN THE TUMOR MICROENVIRONMENT. INFLAMMATORY CYTOKINE SIGNALING INITIATES SIGNALING PATHWAYS LEADING TO THE ACTIVATION OF MASTER TRANSCRIPTION FACTORS (TFS) SUCH AS SMADS, STAT3, AND NF-KAPPAB. MOREOVER, THE SAME INFLAMMATORY RESPONSES ALSO ACTIVATE EMT-INDUCING TF (EMT-TF) FAMILIES SUCH AS SNAIL, TWIST, AND ZEB, AND EPIGENETIC REGULATORS INCLUDING DNA AND HISTONE MODIFYING ENZYMES AND MICORNAS, THROUGH COMPLEX INTERCONNECTED POSITIVE AND NEGATIVE FEEDBACK LOOPS TO REGULATE EMT AND CSC GENERATION. HERE, WE REVIEW THE MOLECULAR REGULATORY FEEDBACK LOOPS AND NETWORKS INVOLVED IN INFLAMMATORY CYTOKINE-INDUCED EMT AND CSC GENERATION. 2019 15 234 22 ADDICTION OF CANCER STEM CELLS TO MUC1-C IN TRIPLE-NEGATIVE BREAST CANCER PROGRESSION. TRIPLE-NEGATIVE BREAST CANCER (TNBC) IS AN AGGRESSIVE MALIGNANCY WITH LIMITED TREATMENT OPTIONS. TNBC PROGRESSION IS ASSOCIATED WITH EXPANSION OF CANCER STEM CELLS (CSCS). FEW INSIGHTS ARE AVAILABLE REGARDING DRUGGABLE TARGETS THAT DRIVE THE TNBC CSC STATE. THIS REVIEW SUMMARIZES THE LITERATURE ON TNBC CSCS AND THE COMPELLING EVIDENCE THAT THEY ARE ADDICTED TO THE MUC1-C TRANSMEMBRANE PROTEIN. IN NORMAL EPITHELIA, MUC1-C IS ACTIVATED BY LOSS OF HOMEOSTASIS AND INDUCES REVERSIBLE WOUND-HEALING RESPONSES OF INFLAMMATION AND REPAIR. HOWEVER, IN SETTINGS OF CHRONIC INFLAMMATION, MUC1-C PROMOTES CARCINOGENESIS. MUC1-C INDUCES EMT, EPIGENETIC REPROGRAMMING AND CHROMATIN REMODELING IN TNBC CSCS, WHICH ARE DEPENDENT ON MUC1-C FOR SELF-RENEWAL AND TUMORIGENICITY. MUC1-C-INDUCED LINEAGE PLASTICITY IN TNBC CSCS CONFERS DNA DAMAGE RESISTANCE AND IMMUNE EVASION BY CHRONIC ACTIVATION OF INFLAMMATORY PATHWAYS AND GLOBAL CHANGES IN CHROMATIN ARCHITECTURE. OF THERAPEUTIC SIGNIFICANCE, AN ANTIBODY GENERATED AGAINST THE MUC1-C EXTRACELLULAR DOMAIN HAS BEEN ADVANCED IN A CLINICAL TRIAL OF ANTI-MUC1-C CAR T CELLS AND IN IND-ENABLING STUDIES FOR DEVELOPMENT AS AN ANTIBODY-DRUG CONJUGATE (ADC). AGENTS TARGETING THE MUC1-C CYTOPLASMIC DOMAIN HAVE ALSO ENTERED THE CLINIC AND ARE UNDERGOING FURTHER DEVELOPMENT AS CANDIDATES FOR ADVANCING TNBC TREATMENT. ELIMINATING TNBC CSCS WILL BE NECESSARY FOR CURING THIS RECALCITRANT CANCER AND MUC1-C REPRESENTS A PROMISING DRUGGABLE TARGET FOR ACHIEVING THAT GOAL. 2022 16 699 22 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 17 6910 20 [TRANSFORMING GROWTH FACTOR-BETA AND RENAL FIBROSIS]. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS A DRIVING FORCE OF RENAL FIBROSIS, WHICH MAY LEAD TO CHRONIC KIDNEY DISEASES AND EVEN END STAGE RENAL DISEASES. BY ACTIVATING CANONICAL AND NON-CANONICAL SIGNALING PATHWAYS, TGF-BETA PROMOTES THE SYNTHESIS OF EXTRACELLULAR MATRIX WHILE PREVENTING THEIR DEGRADATION. IN THE INJURED KIDNEY, TGF-BETA INDUCES APOPTOSIS, PROLIFERATION AND FIBROTIC RESPONSE OF RENAL CELLS INCLUDING EPITHELIAL CELLS, ENDOTHELIAL CELLS, PODOCYTES, FIBROBLASTS, PERICYTES AND MACROPHAGES, AND IT ALSO PROMOTES TRANSDIFFERENTIATION, ACTIVATION AND PROLIFERATION OF MYOFIBROBLASTS. ADDITIONALLY, TGF-BETA EXERTS PROFIBROTIC EFFECTS BY INTERPLAYING WITH OTHER SIGNALING PATHWAYS LIKE BMP-7, WNT/BETA-CATENIN AND MAP KINASE. SMAD3 IS THE CENTRAL PATHOLOGICAL GENE IN RENAL FIBROSIS, AND EPIGENETIC REGULATION OF TGF-BETA/SMAD3 IS A HOT TOPIC IN KIDNEY FIELD. ALTHOUGH DIRECT TARGETING TGF-BETA MAY CAUSE SIDE EFFECTS INCLUDING TUMORIGENESIS AND IMMUNE DISEASES, THE THERAPEUTIC STRATEGIES TARGETING THE BALANCE OF DOWNSTREAM SMAD3 AND SMAD7 MAY PREVENT OR DELAY THE PROGRESSION OF FIBROTIC KIDNEY DISEASE. 2018 18 4674 21 NEW INSIGHTS INTO THE ROLE AND MECHANISM OF PARTIAL EPITHELIAL-MESENCHYMAL TRANSITION IN KIDNEY FIBROSIS. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IS DESCRIBED AS THE PROCESS IN WHICH INJURED RENAL TUBULAR EPITHELIAL CELLS UNDERGO A PHENOTYPE CHANGE, ACQUIRING MESENCHYMAL CHARACTERISTICS AND MORPHING INTO FIBROBLASTS. INITIALLY, IT WAS WIDELY THOUGHT OF AS A CRITICAL MECHANISM OF FIBROGENESIS UNDERLYING CHRONIC KIDNEY DISEASE. HOWEVER, EVIDENCE THAT RENAL TUBULAR EPITHELIAL CELLS CAN CROSS THE BASEMENT MEMBRANE AND BECOME FIBROBLASTS IN THE RENAL INTERSTITIUM IS RARE, LEADING TO DEBATE ABOUT THE EXISTENCE OF EMT. RECENT RESEARCH HAS DEMONSTRATED THAT AFTER INJURY, RENAL TUBULAR EPITHELIAL CELLS ACQUIRE MESENCHYMAL CHARACTERISTICS AND THE ABILITY TO PRODUCE A VARIETY OF PROFIBROTIC FACTORS AND CYTOKINES, BUT REMAIN ATTACHED TO THE BASEMENT MEMBRANE. ON THIS BASIS, A NEW CONCEPT OF "PARTIAL EPITHELIAL-MESENCHYMAL TRANSITION (PEMT)" WAS PROPOSED TO EXPLAIN THE CONTRIBUTION OF RENAL EPITHELIAL CELLS TO RENAL FIBROGENESIS. IN THIS REVIEW, WE DISCUSS THE CONCEPT OF PEMT AND THE MOST RECENT FINDINGS RELATED TO THIS PROCESS, INCLUDING CELL CYCLE ARREST, METABOLIC ALTERNATION OF EPITHELIAL CELLS, INFILTRATION OF IMMUNE CELLS, EPIGENETIC REGULATION AS WELL AS THE NOVEL SIGNALING PATHWAYS THAT MEDIATE THIS DISTURBED EPITHELIAL-MESENCHYMAL COMMUNICATION. A DEEPER UNDERSTANDING OF THE ROLE AND THE MECHANISM OF PEMT MAY HELP IN DEVELOPING NOVEL THERAPIES TO PREVENT AND HALT FIBROSIS IN KIDNEY DISEASE. 2020 19 5920 46 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 5610 29 S100A4/TCF COMPLEX TRANSCRIPTION REGULATION DRIVES EPITHELIAL-MESENCHYMAL TRANSITION IN CHRONIC SINUSITIS THROUGH WNT/GSK-3BETA/BETA-CATENIN SIGNALING. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IS THOUGHT TO BE INVOLVED IN THE TISSUE REMODELING AND LONG-TERM INFLAMMATORY PROCESS OF CHRONIC SINUSITIS (CRS), BUT THE DRIVING MECHANISM IS STILL UNCLEAR. USING HIGH-RESOLUTION MASS SPECTROMETRY, WE PERFORMED A PROTEOMIC SCREEN OF CRS NASAL MUCOSAL TISSUE TO IDENTIFY DIFFERENTIALLY EXPRESSED PROTEINS. DATA ARE AVAILABLE VIA PROTEOMEXCHANGE WITH IDENTIFIER PXD030884. SPECIFICALLY, WE IDENTIFIED S100 CALCIUM BINDING PROTEIN A4 (S100A4), AN EFFECTIVE FACTOR IN INFLAMMATION-RELATED DISEASES, AND ITS DOWNSTREAM PROTEIN CLOSELY RELATED TO TISSUE FIBROSIS COLLAGEN TYPE I ALPHA 1 CHAIN (COL1A1), WHICH SUGGESTED ITS INVOLVEMENT IN NASAL MUCOSAL TISSUE REMODELING. IN ADDITION, STIMULATION OF HUMAN NASAL EPITHELIAL CELLS (HNEPCS) WITH LIPOPOLYSACCHARIDE (LPS) MIMICKED THE INFLAMMATORY ENVIRONMENT OF CRS AND SHOWED THAT S100A4 IS INVOLVED IN REGULATING EMT AND THUS ACCELERATING TISSUE REMODELING IN THE NASAL MUCOSA, BOTH IN TERMS OF INCREASED CELL MOTILITY AND OVEREXPRESSION OF MESENCHYMAL-TYPE PROTEINS. ADDITIONALLY, WE FURTHER INVESTIGATED THE REGULATION MECHANISM OF S100A4 INVOLVED IN EMT IN CRS. OUR RESEARCH RESULTS SHOW THAT IN THE INFLAMMATORY ENVIRONMENT OF CRS NASAL MUCOSAL EPITHELIAL CELLS, TCF-4 WILL TARGET TO BIND TO S100A4 AND REGULATE ITS TRANSCRIPTION. THE TRANSCRIPTION OF S100A4 IN TURN AFFECTS THE EXECUTION OF THE IMPORTANT SIGNALING PATHWAY IN EMT, THE WNT/GSK-3BETA/BETA-CATENIN PATHWAY, THROUGH THE TCF-4/BETA-CATENIN COMPLEX. IN CONCLUSION, THIS STUDY CONFIRMED THAT THE EXPRESSION OF S100A4 WAS SIGNIFICANTLY INCREASED DURING THE PROGRESSIVE EMT PROCESS OF CRS MUCOSAL EPITHELIAL CELLS, AND REVEALED THAT THE TRANSCRIPTIONAL REGULATION OF S100A4 PLAYS AN IMPORTANT ROLE IN THE OCCURRENCE AND DEVELOPMENT OF EMT. THIS FINDING WILL HELP US TO BETTER UNDERSTAND THE PATHOGENESIS BEHIND THE REMODELING IN CRS PATIENTS, AND IDENTIFY TARGET MOLECULES FOR THE TREATMENT OF CRS. 2022